Long string LED boost driver (using aluminum electrolytic capacitors)

The long strings of LEDs commonly found in TV and display backlighting, street lights, and parking garage lights require a current driver capable of producing high voltages. This reference design provides such a driver using the MAX16834, and demonstrates how very-high dimming ratios can be obtained.

All-ceramic capacitor solution for 112W long string LED boost driver

This reference design uses the MAX16834 to create a high-powered LED driver for a very long string(s) of LEDs. The LED current is adjustable with a potentiometer, and can be set as high as 1.5A into as many as 20 LEDs (75V total). For long life, ceramic capacitors are used for both input and output decoupling.

Signal conditioning in industrial multi-channel data acquisition systems using Σ-Δ ADCs

This application note will help the designer of a high-performance, multichannel data acquisition system (DAS) configure the proper interface between industrial sensors and high-performance ADCs. The example used is a power-grid monitoring system. The article explains advantages of the MAX11040K ADC's sigma-delta architecture, and how to select the proper schematic and components to achieve optimum system performance.

VGA 8:1 Multiplexer Reference Design Using the MAX4885

This reference design (RD) features a fully assembled and tested surface-mount printed circuit board (PCB). The RD board utilizes the MAX4885 1:2 or 2:1 multiplexer and other ICs to implement a complete video graphics array (VGA) 8:1 multiplexer. VGA input/output connections are provided to easily interface the MAX4885 RD board with VGA-compatible devices. The RD board gives the option to use a single 5V DC power supply (V+), or this RD board can be powered from any one of the eight VGA sources.

Electricity meter reference design using MAXQ3180/MAXQ3183 AFE

The MAXQ3180 and MAXQ3183 are polyphase multifunction energy measurement analog front-ends (AFEs) with many advanced power-monitoring features such as power factors, vector sum, and harmonic components. Metering accuracy and electric fast transient (EFT) are critical requirements for electric meter designs, and Maxim provides reference designs that have been tested for accuracy and EFT. These designs demonstrate the metering features of the MAXQ3180/MAXQ3183. This application note describes a reference design for evaluating the MAXQ3180/MAXQ3183 as an energy meter. The reference design includes an electricity meter and the companion PC software. Evaluation boards, schematics, bill of materials, and test results are shown.

Single-channel buck converter can drive projector's RGB LEDs by simply adding three power MOSFETs

This application note is an RGB LED driver reference design for a low-power projector. The design features a single MAX16821 HB LED driver to drive the RGB LEDs one at a time. This approach reduces the components needed, resulting in an efficient, small, and economical design. Board layout and test results are shown.

Power chopper dimming controls boost LED driver efficiency and maintains minimum inrush current

This LED driver reference design drives a 700mA constant current to a single string of LEDs with forward voltages up to 60V. The design allows PWM dimming based on supply chopping. The input power supply is chopped on and off at 300Hz to 1kHz frequency to achieve LED brightness control. The driver uses a fixed-frequency boost converter, controlled by the MAX16834 LED driver. This unique reference design limits the input inrush current to negligible levels without compromising either the input or output filtering. Design schematics and test results are provided.

Wide input range, 5V/2.6A output flyback converter

This reference design is for a highly efficient, flyback, 5V Class 3 powered device (PD) with a wide 9V to 57V auxiliary input. The design features the MAX5969B as its controller. The design also uses the MAX5974D, which controls current-mode PWM converters and provides frequency foldback for both the auxiliary input and power over Ethernet (PoE) applications. Using these devices, this reference design is IEEE® 802.3af/at compliant. It is also a high-performance, compact, and cost efficient solution for a Class 3 PD. The design can also support the wide auxiliary-input voltage range to provide 10W output power.

Customized high-performance Class 2 powered devices (PDs) to support Class 3 designs

This reference design is for a highly efficient, flyback 3.3V and 5V Class 2 powered device (PD). The design features the MAX5969B as its controller. The design also uses the MAX5974A, which controls current-mode PWM converters and provides frequency foldback for PoE applications. Using these devices, this reference design is IEEE® 802.3af/at compliant, and a high-performance, compact, and cost efficient solution for a Class 2 PD. The design can also be customized to 3.3V/2A and 5V/1A Class 3 PD.

Efficient, low-cost flyback converter without optocoupler feedback

This reference design is for a highly efficient, flyback, 12V, Class 3 powered device (PD). The design features the MAX5969B as its controller. The design also uses the MAX5974A, which controls current-mode PWM converters and provides frequency foldback for PoE applications. Using these devices, this reference design is IEEE® 802.3af/at compliant and is a high-performance, compact, and cost efficient solution for a Class 3 PD. The design can also be customized to 12V/2A Class 4 PD.

High-precision temperature measurement using advanced thermocouples and high-resolution Σ-Δ ADCs

Many industrial and medical applications require temperature measurements with accuracies of ±1°C or better, performed with reasonable cost over a wide range of temperatures (-270°C to +1750°C), and often with low power consumption. Properly selected, Standardized, modern thermocouples paired with high-resolution ADC data acquisition systems (DASs) can cover this wide temperature range and ensure reproducible measurements, even in the harshest industrial environments.

Active clamp forward, dual-output PD provides high-performance support for POE applications

This reference design is for a highly efficient, active-clamped forward, dual 3.3V/8.8V-output powered device (PD). The design features the MAX5969A and MAX5900 as its controllers. The design also uses the MAX5974C, which controls current-mode PWM converters and provides zero-voltage switching (ZVS) and frequency foldback to enhance supply efficiency. Using these devices, this RD is IEEE® 802.3at compliant and is a high-performance, compact, and cost-efficient solution for PoE and nonstandard high-power PDs. The design can also support the auxiliary input voltage to provide maximum 55W output power.

Low EMI, active clamping, forward Class 4 powered device (PD), providing efficient solutions for PoE applications

This reference design is for a highly efficient and low-EMI active-clamped forward, 5V powered device (PD). The design features the MAX5969B as its controller. The design also uses the MAX5974A, which controls current-mode PWM converters and provides inductive feedback, zero-voltage switching (ZVS), and frequency foldback to reduce cost and enhance supply efficiency for PoE applications. Using these devices, this reference design is IEEE® 802.3af/at compliant, and is a high-performance, compact, and cost-efficient solution for a Class 4 PD. The design can also support the auxiliary input voltage to provide maximum 25W output power.

Layout Considerations for MAX16974/MAX16975/MAX16976 DC-DC Converters

The MAX16974/MAX16975/MAX16976 high-performance DC-DC converters are standard buck controllers designed for automotive applications. This application note explains how to optimize the layout of these ICs. An example layout is provided at the end of the document.

Simple Wireless Bluetooth Stereo Audio System for Outdoors

When people want portable music, they usually rely on battery-powered audio devices. With a bit of engineering blood (or curiosity) running in your veins, it is not difficult to build a wireless Bluetooth® stereo audio system that can be controlled with any device that has a Bluetooth connection and a music player.

Simple wireless temperature monitor also has data logging capabilities

This design idea shows how you can design a simple wireless temperature-monitoring system with data-logging capabilities by using a local temperature sensor and an ASK transmitter and receiver pair.

Modern PRTD temperature sensors and high-resolution delta-sigma ADC enable high-precision temperature measurement over a wide range

Many modern industrial, medical, and commercial applications require temperature measurements in the extended temperature range with accuracies of ±0.3°C or better, performed with reasonable cost and often with low power consumption. This article explains how platinum resistance temperature detectors (PRTDs) can perform measurements over wide temperature ranges of -200°C to +850°C, with absolute accuracy and repeatability better than ±0.3°C, when used with modern processors capable of resolving nonlinear mathematical equation quickly and cost effectively. This article is the second installment of a series on PRTDs. For the first installment, please read application note 4875, "High-Accuracy Temperature Measurements Call for Platinum Resistance Temperature Detectors (PRTDs) and Precision Delta-Sigma ADCs."

Class D, 2.1-channel audio amplifier reference design for MP3 player docking station

This reference design demonstrates the use of the MAX98400 Class D audio amplifier in a stereo audio docking station application. The MAX98400 2.1 demo box is a complete powered speaker dock that uses two MAX98400 ICs to drive a 3-channel speaker system consisting of two 2in satellite speakers and one 5in subwoofer. The reference design is intended to be used with a portable audio player as its main music source. The overall solution size is very compact and features active equalization, power-supply monitoring, and dynamic equalization for the subwoofer.

Level Measurement Systems Using Compensated Silicon Pressure Sensors and Precision Delta-Sigma ADCs, Part 1

This reference design provides design ideas for a cost-effective, low-power liquid-level measurement data acquisition system (DAS) using a compensated silicon pressure sensor and a high-precision delta-sigma ADC. This document discusses how to select the compensated silicon pressure sensor, suggest system algorithms, and provide noise analyses. It also describes calibration ideas to improve system performance while also reducing complexity and cost.

MAX2550-MAX2553 Transceiver Femtocell Wireless Reference Design

The MAX2550 is a complete single-chip radio transceiver for UMTS band 1 femtocell applications. The RD2550 reference design is based on the MAX2550 and contains all of the relevant components necessary to design and build a competitive radio solution to support the base-station transceiver (BTS) frequency band: 1920MHz to 1980MHz (Rx) and 2110MHz to 2170MHz (Tx). The RD2550 also supports downlink monitoring of surrounding macrocells. This enables the system to select the most suitable operating conditions (power, codes, frequencies, capacity, etc.).