Evaluation Printed Circuit Board

The AFBR-775BxxxZ/785BxxxZ transmit/receive pair are high-performance fiber optic modules manufactured for parallel data communication applications over 50/125 mm MM optical fiber. At data rates from 1 to 6.25 Gbps per channel these modules are suitable for applications requiring up to 75 Gbps aggregate bandwidth. Each transmitter/receiver pair completes a robust communication link across 150 meters of optical fiber useful in many datacom and telecom switch and router back-plane connections. 

This application note is intended for use in conjunction with the device data sheet for the respective transmit/receive pair, which is available from your Avago Technologies representative. The data sheet provides a detailed description of the modules operation, signal descriptions and maximum ratings. It is recommended that the block diagrams, pin definitions, and maximum ratings from the data sheet be reviewed prior to testing.

Recommended Equipment List
Test Equipment Included in Sample Kit:

• 12-Channel Pluggable Tx Evaluation Board
  
• 12-Channel Pluggable Rx Evaluation Board
  
• Avago Technologies AFBR-775BxxxZ/785BxxxZ Data Sheet
  
• Application Note 5304

Test Equipment Not Included in Sample Kit:

• 3.3 V dc -Power Supply(s) 2.5 V dc -Power Supply(s)
• 12-fiber Multimode Fiber Optic Ribbon Cable with MTP® Connectors
• 12-fiber Multimode Fiber Optic Breakout-Cable with MTP®-to-SC connectors
• 86100A Agilent Digital Communications Analyzer (DCA)
• Agilent 83487A Opt H21 DCA Plug-In (or equivalent)
• Agilent ParBERT 81250 (or equivalent Bit Error Rate Tester)
• Variable Fiber Optic Attenuator
• Optical Power Meter (multimode, 850nm capable)
• 81002FF Integrating Sphere Adapter (recommended High-frequency coaxial cables with SMA connectors (x48) 

Evaluation Board Description
Top views of the evaluation printed circuit boards are shown in Figures 9 and 10 near the end of this document. Descriptions of the test access points including the high-speed I/O connections and control and sense outputs are listed in Table 1 for the Transmitter and Table 2 for the Receiver. The evaluation boards are 6.4 x 5.15 in.(16.3 x 13.1cm) and are 4-layer PCB with Rogers on top layer dielectric.

Electrical connections from the modules to their respective evaluation PCB are achieved through a 100 pin (10x10) MEG-Array® plug-receptacle [4]. This high-density connector enables the user to easily interchange modules allowing testing of many device pairs using only one set of evaluation boards. The robust design of these pluggable modules allows for repeated plugging and unplugging of the modules up to 50 times without degradation in the receptacle electrical integrity.

Please note that these modules are electrically sensitive devices and are NOT intended for “hot-plug” applications. The power supply to the evaluation boards should be turned OFF prior to plugging or unplugging the devices. “Hot plugging” these devices is not recommended and may result in excessive voltage and or inrush current that exceeds the device limits and may cause damage.

These evaluation boards provide access to all transmit and receive high-speed I/O’s through straight PCB mount SMA connectors. All of the high-speed differential data I/O have 100 nF ac-coupling capacitors on the evaluation boards (ac-coupling is recommended for these modules). The power supplies (2.5V and 3.3V) can be applied through BNC connectors on each board.

Mating Directions

• Ensure the connector assemblies are clean and free of contaminants prior to mating. Locate and match the connector’s position marking (D) for both the Plug and Receptacle. Also ensure that the power (both 3.3V and 2.5V) are not turned on. This will result in the correct orientation of the modules with regard to the evaluation boards. Rough alignment is required prior to connector mating as misalignment of > 0.8 mm could damage the connector contacts. The receptacle is keyed for rough alignment. Application of mating forces should originate from one side of the connector then proceed to the other side of the connector. See Figure 1.

Figure 1  Mating Forces

Unmating Directions

• Release any fasteners holding the assembly together.
• Turn off the voltage to the module (both 2.5V and 3.3V ).
• Force applied during connector unmating needs to originate from the alignment slot/key end of the assembly.
• Unmating the connector perpendicular to the alignment slot/key may cause damage to the terminal contacts. See Figure 2. 

Figure 2  Un-Mating Forces

It should be noted that the transmitter and receiver modules are keyed in such a way that connecting a transmitter module to a receiver footprint or evaluation board and vice-versa is prevented.

To learn more about Evaluation Printed Circuit Board, click here.

Truck/Bus Harness Protection in 24V Battery Systems

TE Circuit Protection has developed overcurrent protections that can also be used as a protection for truck/bus harness. This application note discusses how overcurrent protection products of TE helps protect the wiring-harness architecture found in trucks, buses and other vehicles with electrical systems based on 24 V technology.

Optimized vehicle harness architecture has a hierarchical structure resembling that of a tree with its main power trunks dividing into smaller and smaller branches that use overcurrent protection at each node. Because a hierarchical architecture can use smaller wires and relays on its “smaller branches,” the resulting harness is smaller and lighter, resulting in a cost savings — both in materials and fuel. In addition, a hierarchical or distributed architecture can provide system protection together with fault isolation, thereby reducing warranty costs and increasing customer satisfaction.

Figure 1 shows a simplified version of a partially distributed architecture with each junction box either directly feeding a module or feeding another nodal module which supplies peripheral loads. Unfortunately the sheer number of circuits found in today’s vehicles has made the optimized system hard to realize in practice. With many tens of circuits emanating from the primary power distribution center, it has become almost impossible to position all the subsequent junction boxes so that they are readily accessible and close to the electronics they are intended to feed. 

Figure 1: In a partially distributed architecture, where a module supplies a number of peripheral loads, PPTC devices can allow shorter and smaller wires to be used. Door and HVAC module examples are shown here.

As a result, system designers have resorted to harness design solutions that negate some of the desired end-benefits, such as:

1. (1)  sacrificing wire size optimization and fault isolation by combining loads into one circuit;
   
2. (2)  locating electrical centers where they are only accessible by trained service personnel, at increased cost; and
   
3. (3)  routing back and forth between various functional systems, increasing wiring length, size and cost.

For example, due to the necessity for fuse accessibility, a conventional door module would have separate power feeds for windows, locks, LEDs (light emitting diodes) and mirror functions, each protected by a separate fuse in the junction box. By incorporating PolySwitch resettable PPTC (polymeric positive temperature coefficient) devices in the door module itself, a single power feed can be used. This helps save wire and reduce the cost and size of the junction box. 
 
Using a resettable circuit protection design that does not need to be driver accessible offers a number of solutions that can be used separately or in combination to better optimize harness designs. For example, a single junction box located in the instrument panel can still be employed. Instead of positioning the PPTC devices close to the conventional fuses on the front panel, they can be located inside the box, close to the connectors or on the bottom face of the box. This saves both frontal area as well as reducing the box’s volume, as shown in Figure 2. 

Figure 3 illustrates yet another advantage of replacing conventional fuses with resettable PolySwitch devices. Indeed, using a PPTC device in a dedicated manner (delocalized or not) can allow wire and relay downsizing, thus helping save cost, space and weight. 

To learn more about Truck/Bus Harness Protection, click here.

App Guide for Flat-Panel TV Sets

Your partner for flat-panel TV sets

NXP Semiconductors offers a wide portfolio of advanced solutions for flat-panel TV sets. All are built on our deep understanding of the needs of set designers and manufacturers, and of market requirements.

We can deliver application-specific solutions for reception, drawing on a complete range of silicon tuners that cover all the major standards for hybrid terrestrial, cable and satellite reception. We also support peripheral functions, such as advanced audio and HDMI interfaces, and provide an extensive portfolio of standard products for TVs.

We use next-generation packaging to save space, lower costs, and improve AV content security, and we reduce energy consumption with low-power technologies that dramatically increase efficiency. We design for ruggedness, supplying devices that stand up to intensive use, and we deliver the high integration needed to simplify development, lower BOM and production costs, and reduce time-to-market.

We are known for innovation and our ability to introduce new technologies that set the standard for performance, efficiency, and size. Our new chip-scale package (CSP) devices, for example, have an exceptionally compact footprint yet achieve a new benchmark in mechanical robustness.

We support our customers with a cost-efficient supply chain, and an enterprise-wide commitment to the highest standards of security, quality, and reliability. We also help our customers prepare for the future, by working with them to implement new features, such as 3D, that will drive growth. In short, our customers have the confidence that comes from working with a world-class partner.

 
Primary AC/DC controllers

<75 W flyback controller TEA1738 for primary control of small flat-panel TVs
The TEA1738 supports high-end regulation schemes. For designs that need less sophisticated flyback control, the TEA1733 is recommended.

Features:

• SMPS controller IC enabling low-cost applications
• Large input voltage range (12 to 30 V)
• Integrated OverVoltage Protection (OVP) on pin VCC
• Very low supply current during start-up and restart (typically 10 μA)
• Low supply current during normal operation (typically 0.55 mA without load)
• Overpower or high/low line compensation
• Adjustable overpower time-out
• Adjustable overpower restart timer
• Fixed switching frequency with frequency jitter to reduce EMI
• Frequency reduction at medium power operation to maintain high efficiency
• Frequency reduction with fixed minimum peak current
• Frequency increase at peak power operation
• Slope compensation for CCM operation
• Low and adjustable OverCurrent Protection (OCP) trip level
• Adjustable soft-start operation
• Two protection inputs (e.g. for input UVP and OVP, OTP and output OVP)
• IC overtemperature protection

Silicon tuners

Our portfolio supports compatibility with legacy transmission formats, by covering hybrid analog and digital terrestrial reception. We also support the latest digital standards, along with cable and free-to-air satellite reception. We offer the high performance required by TV set manufacturers, and our software drivers simplify design work even further.

All our tuners deliver excellent performance and are suitable for high-end analog/digital applications. Also, our products have been validated against major standards worldwide.


To learn more about this application guide, click here.

Class-Leading 16-bit Sensor Signal Conditioner

ZMDI is pleased to introduce a class-leading 16-bit sensor signal conditioner (SSC) IC for calibrating resistive sensor modules. The ZSSC3026 combines high-accuracy amplification, 16-bit precision analog-to-digital conversion and an 18-bit DSP for linearization and calibration functions. This high-resolution sensor interface application-specific standard product provides special features for battery-driven low-power devices, an ultra-low standby current and intelligent power-saving technology to ensure lowest overall current consumption. Designed initially for high resolution altimeter module applications, the ZSSC3026 is ideal for use in any device that requires high accuracy and low power consumption.

“Energy-efficiency is what we do best. We enhanced the basic ZSSC30×6-family to provide our customers with the resolution and accuracy required for their next generation products,” stated Frank Schulze, Business Line Manager for Sensing and Automotive at ZMDI. “Unlike many available products today, the ZSSC3026 includes internal signal correction and allows customers to minimize engineering efforts and costs.”

Well-suited for applications in mobile devices, the ZSSC3026 also supports high accuracy industrial and medical applications; e.g., ambient assisted living and industrial pressure sensors. Extended temperature range, 4kV ESD protection and an outstanding power supply rejection ratio (PSR) enable a wide range of products in harsh environments.



To learn more about ZSSC3026, click here.

Introducing the ZL8801 Digital Power Controller

ZL8800/ZL8801
PMBus™ ChargeMode™ Control DC/DC Digital PWM Controllers

The ZL8800 is a dual channel/dual phase controller that utilizes a ChargeMode™ control loop technology to deliver fast transient response without the need for compensation, reducing design time. It provides best-in-class transient response for digital Point of Loads (POLs), saving on output capacitance and board space, important benefits for the advanced power systems found in the latest generation of base-stations, routers, and similar infrastructure designs.

The ZL8801 digital power controller is a dual phase only version of the ZL8800, with added support for DDC current share (up to 4 devices, or 8 phases).

Used in conjunction with Intersil’s easy-to-use PowerNavigator™ GUI, the ZL8800 and ZL8801 digital controllers simplify system power conversion and speed the design process.


To learn more about ZL8800/ZL8801, click here.

3DTouchPad, Multi Finger Touchpad with 3D Gesture Recognition

Last October 9, we discussed about Development Platform with 2D Multi-Touch and 3D Gestures which was brought to us by Microchip Technologies. 3DTouchPad is Microchip’s is a personal computer peripheral used to extend a 2D touch pad with 3D free space gestures. This component utilizes Microchip’s projected capacitive (PCAP) sensor as well as Microchip’s 3D gesture technology, GestIC®. 

The 3DTouchPad offers all features expected from a touch pad (precision, multi-finger tracking, multi-finger surface gestures, such as swipes and scrolling) to which it adds 3D hand gestures. It enables a more efficient, more productive usage of the touch pad area. For example, the 3DTouchPad will allow the user to control the flow of pictures by a wave of the hand or to control the volume of the speakers with a casual rotation. 

No driver installation is needed for the 3DTouchPad; it will simply work out-of-the-box. The 3DTouchPad is designed to be a comprehensive development platform, offering a fully documented Software Development Kit (SDK) as well as an Application Programming Interface (API). The SDK contains reference code and enables the development of applications, drivers and games.

The 3DTouchPad consists of a single four-layer PCB enclosed by a plastic housing. The mini USB port provides connectivity to a USB port of a PC. Three LEDs indicate the operating modes: 2D, 3D and Debug mode. 

Converging Microchip 2D Touch pad solution with 3D gesture recognition based on Microchips GestIC® Technology the 3DTouchPad is a stunning accessory for your daily PC interaction. Without a driver under Win7/8 or MacOS enjoy the precision and speed of a state of the art touchpad, use the 2D surface gesture and enjoy the intuitive support of the build in 3D gestures. Flip through any content (pictures, slides, web browser, …) with a wave of your hand or access the Win8 UI without the need for a touch screen.

Furthermore the 3DTouchPad is a development platform with a compelling SDK, an API and comes with the 3DTouchPad GUI.

The new 3DTouchPad includes driverless, out-of-the-box features for Windows® 7/8.X and OS X®, 3D air gestures, advanced multi-touch performance including surface gestures, and a free downloadable GUI and SDK/API package tailored for developers. The possibilities for this technology also expand beyond the PC market and computer touch pads to include hands-free sanitary products, home automation, remote controls, game controllers, wearable devices and automotive applications. 

Features

• Driverless HID USB connection
• Cursor control
• Win7/8 click events
• 2 finger Pinch/Zoom – coming soon
• 2 finger scroll
• Edge swipes (Windows 8)
• Content flow control by East/West flicks (3D)
• Content scroll
• Close Application by 3D gesture (double flick)
• Maximize windows

Click more to learn about Microchip's 3DTouchPad:
http://www.eeweb.com/company-blog/microchip/3dtouchpad-multi-finger-touchpad-with-3d-gesture-recognition/

High Precision, Long Battery Life Heat/Flow Meter

San Jose, CA—October 6, 2014—Utilities can now improve water- and heat-metering accuracy by an order of magnitude, while operating for up to 20 years on a single "A"-size battery with the MAXREFDES70# ultrasonic flow meter reference design from Maxim Integrated Products, Inc. (NASDAQ: MXIM). 

Traditional mechanical flow meters measure water and heat usage with spinning wheels that easily get out of calibration due to wear from friction and contaminants. This causes inaccurate meter readings and repeated, expensive on-site maintenance costs. Not only do these inaccurate readings reduce revenue, they also prevent leak detection, potentially wasting millions of gallons of clean water a year. The MAXREFDES70# ultrasonic flow meter is the modern alternative to that old technology. This solid-state meter is 10x more accurate than mechanical meters, and 4x more accurate than competitive ultrasonic solutions. This accurate measurement is done without the use of heavy batteries, and the flow meter uses a single "A"-size battery that can last up to 20 years. Measuring as little as 0.5 liters of water per minute with better than 1% accuracy, its fast ultrasonic pulses can be customized to the pulse frequencies required by flow conditions. It can detect even minor leaks that the mechanical meters will never find. With no moving parts, the MAXREFDES70# flow meter is highly resistant to contaminants, subject to less wear, and requires virtually no maintenance. It features no compromises, as it maximizes uptime and provides the most accurate data possible. In this era when natural resource consumption must be carefully managed, this complete, ready-to-use flow meter reference design lets utilities and other industrial flow-measurement applications get to market quickly with the necessary accuracy and precision.

At the heart of the MAXREFDES70# reference design is the new MAX35101, a complete time-to-digital converter with analog front-end (AFE) that measures the difference of upstream and downstream ultrasonic pulses. Supporting flow measurement at low rates (< 30 l/hr), the MAX35101 offers the highest time-to-digital conversion accuracy (20ps) on the market today.

Key Advantages

• Improved low-flow accuracy: time-to-digital accuracy of 20ps (4x better than competitive ultrasonic designs) with early edge detect and multihit capability.
• Easy to implement: free schematics, layout files, and firmware are available for immediate use and customization; an evaluation (EV) kit with the MAXREFDES70# board, transducers, and USB interface is available with evaluation software.
• Low power: uses one "A"-size battery running with 4Ahr capacity, and provides up to 20 years of battery operation.
• High integration: integrates a complete, high-speed time-to-digital converter (MAX35101) with 4ps resolution; an AFE sends and receives the pulses for external transducers.

Click the link below to learn more about "MAXREFDES70#":
http://www.eeweb.com/company-blog/maxim/high-precision-long-battery-life-heatflow-meter/

Excerpt from The Psychology of Automotive LED Lighting

When we think of automotive lighting, our first thoughts often go to high-performance headlamps, bold taillights, and running lights that create strong branding statements. While these trends continue, LEDs are also used as general ambient lighting. What started out as an indicator light application has given way to slick-looking backlit displays, practical-minded occupancy detection and all manner of ambient lighting based on attempts to affect occupant mood, the time of day, and other environmental factors. 


Here, ambient lighting refers less to instrument panel lighting than to the indirect interior illumination that gives the driver a sense of orientation and spaciousness as well as feelings of safety, comfort, and even a sense of pride in value. Ambient lighting delivers an emotional atmosphere and, according to carmakers, ties together exterior and interior lighting conditions for the driver for decreased levels of driving fatigue. 


Ambient lighting is now incorporated into innovative turn- and brake-lighting applications, backlit displays, occupancy detection, night vision, and more. Lighting can actually make us feel differently about our driving and ourselves. Ambient lighting makes a statement as well as an impact on the driving experience. 

The Psychology of Color and Light


People are used to evaluating the color of light in home and office. There is a real impact and psychological effect of warm or cool lighting in our environment that relates to eye fatigue, wakefulness, circadian rhythms and mood. For example, yellow light is seen as warm and pleasant, while bright white light is seen as clean and efficient. Automakers have determined that color and lighting can go much deeper than a mere visual impression.


A variety of emotions can be encouraged with certain hues. BMW engineers and the Lighting Engineering Group at Ilmenau University of Technology in Munich conducted a benchmark study on automotive interior lighting in 2009. The study involved a series of questions answered by participants after driving a real but stationary car with ambient lighting in a simulated environment. Tests performed involved changes in lighting color, luminance and the position of lights in a simulated driving environment. The emotional states of the participants were gauged at the beginning and end of the tests.


Elements within the study included design aspects (such as shape and material) and design principles (such as intended sportiness or luxury.) Purely functional aspects were also considered. Some participants were exposed to blue lighting and others to orange. The results showed that the blue lighting appeared brighter than orange lighting; drivers were able to find automotive control buttons and knobs easier in blue light, and blue lighting also gave drivers a better feeling of their orientation in low-light conditions. The downside of blue lighting was that it was considered "uncomfortable." In comparison, orange ambient lighting gave the perception of luxuriousness and better quality. With increasingly brighter levels of light, participants became more distracted and asked to be able to control it.


Results also found that carefully designed ambient lighting can decrease night-driving fatigue and is important for brand identity. Ambient lighting was shown to enhance night-driving safety and increase appreciation of the vehicle. The study indicated that ambient lighting can enhance the perception of spaciousness and quality of materials. 

Today's Applications


LEDs are used in ceiling dome and map lights, backlit instrument panels, displays, controls, gear sticks and in door-panels to assist the driver as he or she enters, exits, and operates the vehicle. Interior lighting provides indirect illumination and provides a “wow factor” for design.


To date, many studies have researched the effects of lighting on mood, emotion and perception in buildings. Several studies exist on the effects of lighting on vision or safety in automobiles, but to date, a BMW study from 2009 has provided the most information regarding the psychological effects of automotive ambient lighting. Mercedes, Jaguar, and Land Rover are using LED ambient lighting to differentiate their vehicles. Mercedes offers a choice of seven colors with five dimming levels and four diming zones.


LEDs are also evolving with technology as exterior automotive headlamps. LED in headlamps have not only greatly lengthened life and increased efficiency. LEDs are much more flexible than incandescents in how they are able to automatically adapt to surrounding ambient light, and they are so small and light weight that they can be mounted with adhesives, screws, clamps, solder, or via any means that enables heat to adequately and evenly dissipate away from the LED. Newer, tougher semiconductor materials such as Galium Nitride (referred to as a “wide band gap” material ) enable operation at higher temperatures and with greater energy efficiency than LEDs of just 10 years ago.

LEDs have not only enabled specific customization of ambient interior lighting for color, brightness, intensity, and automatic adjustment to environmental changes, but exterior-use LEDs offer the same features in very high power, high brightness LED lighting a range of colors, too. For example, OSRAM Opto Semiconductors offers a broad selection of LEDs and modules that identify precise color, like the OSTAR Headlamp Pro: "The color coordinates of the LEDs correspond to the white field of ECE/SAE, in which the red component of the LED is greater than 5%...." LEDs are a technology that enable specifications for something we take for granted every day…light…and specifications enable designers to influence the automotive experience in precise, repeatable ways.


 To read more about "The Psychology of Automotive LED Lighting", click on the link below:
http://www.eeweb.com/company-blog/mouser/the-psychology-of-automotive-led-lighting/

Compact Washing Machine Filters

LCR Electronics specializes in the design and manufacture of EMI filters and suppression components, electronic and motor control boards as well as a variety of EMC testing, engineering and contract manufacturing services. We have expertise in appliance, military and aerospace, commercial, industrial, telecommunications and medical markets.

LCR manufactures a complete range of high quality standard and customized EMI filters for appliances as diverse as portable tools, vacuum cleaners, blenders, mixers, white goods, pumps, floor care equipment, treadmills, microwave ovens and power supplies. 

Our new 095/02 Series utilizes cost-effective metalized film technology, which helps reduce component cost, while providing better safety characteristics, high reliability and fail-safe characteristics similar to more expensive, older technologies, such as impregnated paper-foil.

Our EMI & RFI Filters bring appliance products into compliance with all National (FCC) and International (CE,VDE, etc.) EMC regulations.

LCR is renowned internationally for our high quality, cost-effective and unique EMC solutions as well as our quick turn-around times for custom EMI & RFI filters -- custom prototypes within one week, and production quantities in four weeks.



Learn more about LCR Astrodyne's Compact Washing Machine Filters:
http://www.eeweb.com/company-news/astrodyne/compact-washing-machine-filters

MLX90614 Grounding and Layout

The MLX90614 is an Infra Red thermometer for non contact temperature measurements. Both the IR sensitive thermopile detector chip and the signal conditioning ASIC are integrated in the same TO-39 can. Integrated into the MLX90614 are a low noise amplifier, 17-bit ADC and powerful DSP unit thus achieving high accuracy and resolution of the thermometer.

Scope
 
Virtually any electronic device needs proper layout, grounding and power supply bypassing. The MLX90614 IR thermometers have simple requirements in this aspect. These are described in the following document.

Decoupling
 
The MLX90614 is a mixed signal device that operates with small sensor signals. The digital part of the device generates switching noise. However, the MLX90614 is a low power device, designed with care for low noise and this noise can be easily nullified with a single capacitor on the power supply pin.

The 5 volt supply voltage version – the MLX90614Axx - uses internal voltage regulators. Their Power Supply Rejection is beneficial in noisy systems.

There are two basic modes of operation of the MLX90614 – SMBus and PWM. (Thermal relay mode uses the same application circuits as PWM.) PWM is free running, with only one output pin and is thus more robust to conducted noise. The application schematic of the MLX90614 in PWM mode is shown on Fig. 2.

Layout
 
General EMC rules apply for the MLX90614 layout. The power supply bypass capacitor needs to be close to both Vdd and Vss pins of the device.

Traces to that capacitor should be short and wide. Supply decoupling needs to be effective for RF and added inductance constrains the performance of the capacitor. For the same reason through hole components are not recommended for decoupling. Electrolytic capacitors are not effective for high frequencies, but paralleling them with appropriate ceramic capacitors is beneficial in wider frequency range.

Conclusion

The MLX90614 IR thermometers are not highly demanding regarding power supply decoupling, grounding and layout. Unlike other mixed and low signal devices all they need is a single ceramic capacitor close to the power and ground pins. The metal can package is beneficial for EMC in a wide frequency range. The MLX90614 is a low power device and generates very little noise.


It is virtually impossible to provide an EMI solution that is appropriate in all cases. Specific EMI can demand more sophisticated solutions, but most applications can adopt the MLX90614 with very little effort.



Learn more about MLX90614:
http://www.eeweb.com/company-blog/melexis/mlx90614-grounding-and-layout

16-Bit Isolated Input AFE

Maxim Integrated, a company with 20 manufacturing plants in 20 separate locations, in 17 different countries. The company has made remarkable breakthroughs that help in the advancement in electronics technology. At Maxim, we know that our actions impact the world around us … and we want that. It's our responsibility to respect the world where we all live and work. But there's more to this story. We must ensure that our impact is a positive one. 

Introduction

In industrial control and industrial automation applications, high-resolution data converters are often required. Although today's field programmable gate arrays (FPGAs) and microcontrollers may integrate analog-to-digital converters (ADCs), in many cases, the resolution is not high enough and isolation is lacking. The Campbell (MAXREFDES4#) subsystem reference design is a 16-bit high-accuracy industrial analog front end (AFE) that accepts a 4–20mA current loop or a 0.2V to 4.096V voltage input signal, and features isolated power and data—all integrated into a small form factor. The Campbell design integrates a precision low-noise buffer (MAX44250), a high-accuracy ADC (MAX11100), an ultra-high-precision 4.096V voltage reference (MAX6126), 600VRMS data isolation (MAX14850), and isolated/regulated 5V power rails (MAX256/MAX1659). This AFE solution can be used in any application that needs high-accuracy analog-to-digital conversion, but it is mainly targeted for industrial sensors, industrial automation, process control, programmable logic controllers (PLCs), and medical applications.

  

Detailed Description of Firmware for ZedBoard Platform

The Campbell firmware design is also developed and tested for the ZedBoard kit and targets an ARM^® Cortex^® -A9 processor placed inside a Xilinx Zynq system-on-chip (SoC). 

An AXI MAX11100 custom IP core is created for this reference design to optimize the sampling rate and SPI timing stability. 

The firmware is a working example of how to interface to the hardware, collect samples, and save them to memory. The simple process flow is shown in Figure 2. The firmware is written in C using the Xilinx SDK tool, which is based on the Eclipse open source standard. Custom Campbell-specific design functions were created utilizing the AXI MAX11100 custom IP core. The SPI clock frequency is set to 4.54MHz when a 189.4ksps sampling rate is selected. The SPI clock frequency is set to 2.5MHz for all other sampling rate. 

 

The firmware accepts commands, writes statuses, and is capable of downloading blocks of sampled data to a standard terminal program via a virtual COM port. The complete source code is provided to speed up customer development. Code documentation can be found in the corresponding firmware platform files.  

Quick Start

Required equipment:

• Windows^® PC with two USB ports
• Campbell (MAXREFDES4#) board
• Campbell-supported platform (i.e., Nexys 3 development kit or ZedBoard kit)
• 4–20mA current loop sensor or other signal source

To learn more about Campbell (MAXREFDES4#), click on the link below:

http://www.eeweb.com/company-blog/maxim/16-bit-isolated-input-afe/


 

*Note*

ARM is a registered trademark and registered service mark of ARM Limited.
Audio Precision is a registered trademark of Audio Precision, Inc.
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
Cortex is a registered trademark of ARM Limited.
Eclipse is a trademark of Eclipse Foundation, Inc. 
Halo is a registered trademark of Halo Electronics, Inc.
MicroBlaze is a trademark of Xilinx, Inc.
Nexys is a trademark of Digilent Inc.
Pmod is a trademark of Digilent Inc.
Spartan is a registered trademark of Xilinx, Inc.
Windows is a registered trademark and registered service mark of Microsoft Corporation.
Xilinx is a registered trademark and registered service mark of Xilinx, Inc.
ZedBoard is a trademark of Avnet, Inc.
Zynq is a registered trademark of Xilinx, Inc.

Allegro A4915 Demo Board

The Allegro A4915 Three-Phase MOSFET Driver’s innovative speed input and fully integrated block commutation delivers simple speed control of a BLDC motor with a single analog voltage. Presented by Dan Jacques, Strategic Marketing Manager, Motor Driver ICs.

The A4915 is designed for pulse width modulated (PWM) current control of 3-phase brushless DC motors. The A4915 is capable of high current gate drive for 6 all N-channel power MOSFETs. An internal charge pump ensures gate drive down to 7 V supply and provides limited gate drive down to 5 V. A bootstrap capacitor is used to generate a supply voltage greater than the source voltage of the high side MOSFET, required for N-channel MOSFETs.

Internal synchronous rectification control circuitry is provided to improve power dissipation in the external MOSFETs during PWM operation. Internal circuit protection includes latched thermal shutdown, dead time protection, and undervoltage lockout. Special power up sequencing is not required.

The A4915 is supplied in a 28-pin TSSOP with an exposed thermal pad (suffix LP) and a 28-contact 5 × 5 mm QFN with an exposed thermal pad (suffix ET). These packages are lead (Pd) free, with 100% matte-tin leadframe plating.



To learn more about Allegro's A4915, click on the link below:
http://www.eeweb.com/company-blog/allegro_microsystems/allegro-a4915-demo-board/

Designing at Very High Voltages

Some people would say designing low voltage products pose minimal challenge to the makers. Only a few specifications and requirements need to be met. But when designing high voltage products, it is the other way around. Mouser Electronics are finding ways to address its clientele's need. 

Mouser Electronics is a worldwide leading authorized distributor of semiconductors and electronic components for over 500 industry leading suppliers. We specialize in the rapid introduction of new products and technologies for design engineers and buyers. Our extensive product offering includes semiconductors, interconnects, passives, and electromechanical components. 

In 2007, Mouser became a part of the Warren Buffett Berkshire Hathaway family of companies. Today, Buffett's holdings include insurance and finance subsidiaries and a host of almost fifty businesses ranging from jewelry and furniture to manufactured homes.

Mouser has a strong commitment to customer service. That’s why we’ve won awards for our legendary worldwide customer service excellence. We understand the value of having a knowledgeable person there to answer your questions quickly. Mouser is redefining customer-focused distribution.

The Need for High Voltage

Given the challenges and risks, why do design engineers even consider using these voltages at all? It's either because the engineer has no choice, or because it's a really good and necessary idea. The applications fall into two broad groups:

In the realm of "the engineer has no choice," scientific, medical, and physics instrumentation need high voltages in specialized equipment such as X-ray machines, to develop high-intensity fields, ionize atoms, and accelerate electrons and other particles. The same applies to vacuum tubes that still need high-power broadcasting or even moderate-power microwave and mm-wave transmitters. In a more common application, even a commercial neon sign needs several kV to ionize the noble gases inside. Note that many of these applications require kilovolts and more, but at relatively modest currents of around 100mA.

In cases where using high voltages is a "really good and necessary idea," engineers are designing for power and efficiency. When a power supply or motor needs to produce large amounts of power, the source must deliver watts, which are the product of voltage and current. But at lower voltages the currents are obviously higher, so IR (current X resistance) losses in conductors, connectors, switches, and active devices cause inefficiency, losses, and I²R heating.

Start With Physical Dimensions

Dealing with high voltage begins with conductor spacing and associated dimensions. The critical terms for spacing conductors at higher voltages are creepage and clearance.

• Creepage is the distance an arc may travel measured over a surface, such as between two traces on a printed-wiring board or across the surface of a connector or IC.
• Clearance is the shortest distance an arc may travel through air, such as from the pin-to-pin of a connector or IC.

The creepage and clearance requirements are a function of the peak voltage; for a sine-wave AC signal, the peak value is 1.4 times the RMS value, plus a substantial safety factor. While it would be nice to be able to call out specific creepage and clearance dimension requirements at any given voltage, it is not possible to do so because their dimensions depend on many factors:

1. Whether it is a potential shock hazard or only a functional-breakdown issue,
2. The region of the world: different zones have different standards,
3. The application: scientific, industrial, or medical, for example, or even a consumer product,
4. Maximum operating altitude and humidity (dry air at sea level has a flash-over rating of about 4kV /cm, or 10kV/inch),
5. Across PC boards and other surfaces: the degree of potential contamination that may be expected due to various kinds of pollution; the PCB material group; and the coating (if any).

Therefore, some serious research is needed to determine the required minimum creepage and clearance values, or engineers may need to call an experienced consultant, especially if the end product will need formal regulatory approval for manufacturing and sale.


To learn more about this article, click on the link below:
http://www.eeweb.com/company-blog/mouser/designing-at-very-high-voltages/

Low Cost Compact DC/DC Converters

Nowadays, power adapters should always have higher efficiency, lower cost, and better adaptability than their predecessors. Consumers prefer to buy electronic equipments with those characteristics. This poses more challenges to the designers to address the "need" of the consumers.

MicroPower Direct (MPD) was founded by a group of industry veterans in 1999. Located in Stoughton, MA (just south of Boston), our steady growth is driven by a commitment to delivering innovative, high quality power conversion products at the lowest possible prices. we currently offer over 5,000 low cost standard "off-the-shelf" DC/DC converters, AC/DC power supplies, high brightness LED drivers, IGBT drivers and switching POL regulators.

Component selection and layout are carefully considered at the design stage to optimize product reliability. All manufacturing is in ISO9000 registered factories under strict quality control system guidelines. All products are supported worldwide, and carry a standard three year warranty.

This month, MPD announces its newest series which is ideal for 20 W DC/DC converters. Introducing, the MPD F2000ERW series. It comprises of 27 different part numbers that have their own specifications. Specifications like nominal voltage, full-load current, no-load current, efficiency, and 7 more specs.


Features

• 20W Output Power
• 2:1 Input Voltage Range
• 1,500 VDC Isolation
• Single & Dual Outputs
• Efficiency to 86%
• Compact 1.6 × 2 In. Case
• -40°C to +71°C Operation
• Industry Standard Pin-Out
• Lowest Cost!!

Click below to know more about this MPD product as well as its data sheet.
http://www.eeweb.com/company-news/micropower_direct/low-cost-compact-dcdc-converters/

Medical Electronics: Challenges for Designers

Hospitals are built to save lives. But are the equipments efficient enough to save lives with minimal loses or close to zero fatality? Making medical equipments perform to its optimum potential poses various challenges for the designers.

Founded in 1994, Astrodyne is a global developer and manufacturer of power conversion solutions that protect and enhance peoples’ lives, with a focus on advanced Medical, Military, Aerospace, and Industrial applications worldwide. Our products are found in some of the most demanding situations – from life-saving heart assist devices, to missile systems, to ruggedized satellite communication systems, to sensitive test and analytical systems. Our headquarters are in Mansfield, MA.

Astrodyne specializes in AC/DC power supplies, AC/DC adapters, DC/DC Converters, Hi Reliability Power Converters, LED Drivers, Linear Transformers, Medical Power Supplies, COTS Power Supplies, Ultra Low Leakage Power Supplies, Medical Isolation Transformers. 

The constant monitoring of patients from the time they step into a hospital, the desire to reduce healthcare spending around the world, an aging population that requires increased levels of supervision and medical intervention, the capacity to deal with baby boomers — these are the most important factors that are driving the medical electronics industry today. Recently, we conducted a forum among industry experts from a variety of manufacturers to discuss issues and challenges the medical electronic industry faces.

Electronic Products: I’d like to focus on miniaturization, which I believe is the most significant trend that is influencing the design of medical devices that would be everywhere from imaging all the way through patient monitoring, through smart drug delivery systems to implantable electronics. What challenges and issues do designers face today and what is your perspective on how these issues can affect the design and part selection process?

 
Peter Resca (Director of Engineering, Astrodyne): I think from the power supply side certainly on the portability and on battery operated, untethered as mentioned, we certainly see low power consumption as being an important driver there. On the other side, and at times it’s the battery charging side. What we see from customers is one of two things:

One, they either take the power external and incorporate an external adapter. We’ve seen more of that in the medical arena. Or on the internal side, what we’ve seen is a lot of — and this sort of echoes what Todd said about systems engineering — getting involved with the customers earlier so that the power supply can provide the EMC support and meet the EMC regulations which maybe in the past have been carried by an external filter or an additional filter and also the isolation barrier which in the past maybe was carried by an external transformer, further reducing the overall footprint.


To learn more about Medical Electronics, click on the link below:
http://www.eeweb.com/company-blog/astrodyne/medical-electronics-challenges-for-designers

High Performance 10-Bit D-Type Flip Flop

The electronics industry is being driven by four mega trends that are helping shape our society: Energy Efficiency, Connected Devices, Security and Health. Connecting to these trends and enabling Secure Connections for a Smarter World, NXP Semiconductors N.V. creates solutions for the Connected Car, Cyber Security, Portable & Wearable and the Internet of Things. Through our innovations, customers across a wide variety of industries – including automotive, security, connected devices, lighting, industrial and infrastructure – are able to differentiate their products through features, cost of ownership and/or time-to-market.

 

NXP has developed a 10-bit D-type, positive-edge trigger, and 3-state flip-flop, the 74ABT821. It is a high-performance BiCMOS device which combines low static and dynamic power dissipation with high speed and high output drive. Its bus interface register is designed to eliminate the extra packages required to buffer existing registers and provide extra data width for wider data/address paths of buses carrying parity. 

The 74ABT821 is a buffered 10-bit wide version of the 74ABT374A.

The 74ABT821 is a 10-bit, edge-triggered register coupled to ten 3-state output buffers. The device is controlled by the clock (CP) and output enable (OE) control gates.The register is fully edge triggered. 

The state of each D input, one set-up time before the LOW-to-HIGH clock transition is transferred to the corresponding output Q of the flip-flop.

The 3-state output buffers are designed to drive heavily loaded 3-state buses, MOS memories, or MOS microprocessors.

The active LOW output enable (OE) controls all ten 3-state buffers independent of the register operation. When OE is LOW, the data in the register appears at the outputs. When OE is HIGH, the outputs are in high-impedance OFF-state, which means they will neither drive nor load the bus. 

Features and Benefits

• High-speed parallel registers with positive-edge triggered D-type flip-flops
• Ideal where high speed, light loading, or increased fan-in are required with MOS microprocessors
• Output capability: +64 mA and -32 mA
• Power-on 3-state
• Power-on reset
• Latch-up protection exceeds 500 mA per JESD78B class II level A
• ESD protection:
  
  • HBM JESD22-A114F exceeds 2000 V
  • MM JESD22-A115-A exceeds 200 V

To learn more about NXP 74ABT821, click on the link below:
http://www.eeweb.com/company-news/nxp/high-performance-10-bit-d-type-flip-flop/

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Epoxy Formulation for Electronic Applications

This week we will again be discussing various advancements in the field of electronics. First, we will discuss about Master Bond's Epoxy Formulation for Electronic Application.

Master Bond Inc. was founded in 1976. Our focus has been on developing the best in epoxies, silicones, polyurethanes, polysulfides, UV cures and other specialty adhesive systems. We are true specialists in our field and are recognized by many as the preeminent adhesive formulation company in the world.

Through research and development, we have been able to create innovative, new compounds with truly unique properties. This effort has been led by our Technical Director, Dr. Walter Brenner. Dr. Brenner received his Ph.D. in Polymer Chemistry from Brooklyn Polytechnical Institute. He is a renowned Professor of Chemical Engineering and has served as a consultant for various U.S. Government agencies. He holds numerous patents and is credited with being the first person to develop electron beam radiation curing.

Master Bond has added another polymer system which has a lower viscosity, two component, flexibilized epoxy resin system for high performance bonding, coating, sealing and encapsulating. EP21FL is formulated to cure at room temperature or more rapidly at elevated temperatures, with a four to one mix ratio by weight. 

It is formulated to cure at room temperature or more rapidly at elevated temperatures, with a four to one mix ratio by weight. This compound is 100% reactive and does not contain any solvents or volatiles. It bonds well to a variety of substrates, including metals, glass, ceramics and many plastics. Since it is a toughened system, it is ideal for bonding dissimilar substrates with differing coefficients of expansion. EP21FL is effective for bonding surfaces subjected to rigorous thermal cycling as well as thermal and mechanical shocks. EP21FL is a wonderful potting compound, particularly for larger encapsulations. Its excellent electrical insulation properties are especially significant. EP21FL features an exceptionally long working life, along with a low exotherm while curing. It is resistant to chemicals including water, oils, salts, etc., over the wide temperature range of -100°F to +250°F. Part A is transparent and the color of Part B amber-clear. Master Bond EP21FL is widely used in electronic, electrical, optical and aerospace application, among others.

Product Advantages

• Convenient mixing: four to one ratio by weight.
• Toughened epoxy ideal for bonding dissimilar substrates subjected to rigorous thermal cycling.
• Lower viscosity; easy applied for bonding, coating and encapsulation.
• Versatile cure schedules: ambient temperature cures or faster, elevated temperature cures.
• Low exotherm, appropriate for larger castings.
• Superior durability, thermal shock and chemical resistance.
• Outstanding ability to withstand thermal cycling.
• Excellent electrical insulation properties.
• Exceptionally long working life.

To learn more about Master Bond's EP21FL, click on the link below:
http://www.eeweb.com/company-news/master_bond/epoxy-formulation-for-electronic-applications

Buck-Boost and Boost+Bypass Switching Regulators

Now for the our last discussion for this week, we will be having Intersil's Buck-Boost and Boost+Bypass Switching Regulators. For this past few days, we have discussed various advancements in the field of electronics. We had Mouser's MEMS, both of IXYS' power electronics and differential ultra-fast laser diode driver, Coilcraft's inductors, Microchip's development platform with 2D multi-touch and 3D gestures, and Allegro's A4915.

Intersil's ISL911xx family of buck-boost and boost switching has expanded with the addition of five new devices. This family is designed to support system power supplies and peripherals like Wi-Fi- or 3G/4G RF power amplifiers. These five new devices include the ISL91106 and ISL91107 buck-boost regulators, and the ISL91132, ISL91133 and ISL91134 high-efficiency boost+bypass regulators. Intersil’s proprietary four-switch buck-boost architecture extends battery life by enabling industry leading efficiency of up to 96% and providing smooth transitions from buck to boost to prevent glitches and noise in smartphones, tablets and other single-cell lithium ion (Li-ion) or Li-polymer battery systems.

The ISL9110x buck-boost regulator family is capable of working with the ultra-small inductors and capacitors to fit within less than 14mm² board footprint, making them the ideal 2A switching converter solution for space-constrained mobile devices. The advanced wafer-level CSP package requires only a single inductor and very few external components, which minimizes overall space requirements. The ISL911xx regulators’ 2.5MHz switching frequency further reduces the power supply solution size.

BUCK-BOOST REGULATORS

ISL91106, ISL91107 and ISL91108 are highly-integrated buck-boost switching regulators that accept input voltages either above or below the regulated output voltage. Unlike other buck-boost regulators, these regulators automatically transition between operating modes without significant output disturbance.

The ISL91110 is a high-current buck-boost switching regulator for systems using new battery chemistries. It uses Intersil’s proprietary buck-boost algorithm to maintain voltage regulation while providing excellent efficiency and very low output voltage ripple when the input voltage is close to the output voltage.

BOOST REGULATORS

The ISL91132, ISL91133 and ISL91134 are integrated boost switching regulators for battery powered applications. These devices provide a power supply solution for products using a one cell Li-ion or Li-polymer battery.
ISL91117 is a highly-integrated boost switching regulator for battery powered applications. The device provides a power supply solution for products using dual-cell or three-cell alkaline, NiCd or NiMH, or one-cell Li-ion or Li-polymer battery.

To learn more about Intersil's ISL911xx, click on the link below:
http://www.eeweb.com/company-news/intersil/buck-boost-and-boostbypass-switching-regulators