REP021: Front-end devices for 2.5GHz Globalstar and IS-95

This reference design (RD) is for a dual-band CDMA front-end IC that uses a PCS-band signal path for 2.5GHz LEO satellite channel and a cellular-band signal path for GlobalStar IS-95 CDMA applications. The MAX2323 LNA plus mixer for dual-band CDMA handsets is featured.

Schematic PCB

High performance 1-Wire network driver

This document describes a microcontroller-based 1-Wire® master interface for reliable operation of small, medium, and large 1-Wire networks. This is accomplished using careful impedance matching, intelligent (software-controlled) active pullup, and slew-rate control. Software flow charts are included to assist the user in generating the correct 1-Wire timing for reset pulse, presence detect, write one, write zero, and read time slots using any suitable microcontroller. Scope traces illustrate the timing performance of the driver as well as transmission line effects as they appear with long cables.

Designing robust, fault-tolerant motion control feedback systems

This article reviews basic servo systems and development of the fault-tolerant feedback systems for servo systems. Controller receiver circuit design, proper PC-board receiver circuit layout, and the encoder's signal cable and termination are discussed. Additionally, various types of industrial feedback encoders are presented, along with the various types of faults that can develop in a servo feedback system.

Complete solution for low-cost electrical equipment including 12V buck converter

The MAX5953A provides a simple and inexpensive, yet complete, nonisolated power solution for a powered device (PD) in a Power-over-Ethernet (PoE) system. The circuit provides the PD with detection and classification signatures in compliance with the IEEE^SM 802.3af standard, plus programmable inrush-current control, an integrated power switch, a PWM controller, and integrated high- and low-side switches. The buck step-down converter is capable of > 80% conversion efficiency while delivering 12V at 0.85A.

Optimize the load switching function of DS2715 battery charger

Integrating a battery-load switch function into a smart-charger IC greatly benefits low-cost applications. The DS2715 battery-charger IC intelligently senses battery loading after removal of the charge source to seamlessly maintain power to connected loads. This application note details examples of several application circuits that optimize the performance of the DS2715. Specifically, it presents a circuit for applications in which the DS2715 is connected to noncontinuous loads, and a circuit for powering the load directly from batteries.

MAX2160 ISDB-T Reference Design

This reference design for the MAX2160 tuner plus demodulator IC demonstrates a compact daughter-board solution for the ISDB-T standard (single-segment). This design converts UHF band signals (470MHz to 770MHz) to a MPEG-2 transport stream. The solution is intended for portable applications, such as cell-phone TVs and PDAs.

Choosing the Right 1-Wire Host for Your Embedded Application

This application note presents four categories of 1-Wire master circuits for embedded applications and discusses their capabilities and requirements in relation to available (ie, unused) system resources. The schematics shown here apply to short networks that do not extend beyond the radius of 1 meter and are populated with a small number of 1-Wire slaves. Instructions and a decision worksheet are included to identify the most cost-effective 1-Wire master for the application. The reader should be familiar with the basics of 1-Wire communication and microcontrollers.

MAX2165 DMB-TH USB Dongle Reference Design

This compact USB dongle design combines a MAX2165 direct-conversion tuner and a DMB-TH demodulator. The design converts a UHF signal (470MHz to 858MHz) to a MPEG-2 transport stream. Then the USB interface enables video viewing on a laptop or desktop computer.

MAX3541 DVB-T/PAL Tuner

The MAX3541 is an integrated, single-conversion terrestrial tuner IC for DVB-T and PAL. The device is designed to convert input signals in the VHF-Low, VHF-High, and UHF bands to an IF frequency of 36MHz. The MAX3541 is designed for television, analog/digital terrestrial receiver, and digital set-top box applications.

802.11b/g RF front-end module reference design using the MAX2830

This module uses the highly integrated MAX2830 RF transceiver. It is a complete RF front-end solution that meets the WLAN IEEE^SM 802.11b/g standard. The transmitter can deliver more than 15dBm Tx power at EVM < 5.6% with a 54Mbps OFDM 802.11g signal. The receiver can provide an IQ signal EVM < 9% with a -74.5dBm 54Mbps OFDM 802.11g signal.

900MHz full-duplex wireless transmitter reference design

This reference design covers the design of a transmitter inside a 900MHz full-duplex radio using the MAX2902 single-chip transmitter. The MAX2902 is designed for use in the 868MHz to 915MHz frequency band, and complies with FCC CFR47 part 15.247 902MHz to 928MHz ISM band specifications. The reference design is capable of delivering more than +19dBm with V _CC = 2.9V and I _CC = 170mA, and +20dBm with V _CC = 3.3V and I _CC = 190mA, while meeting 14dB of CNR (1.22Mbps BPSK) at 10:1 VSWR (all angles).

MAX2120 DVB-S Half-NIM Tuner Reference Design

This reference design is a commercial Half-NIM DVB-S tuner that uses Maxim's MAX2120 satellite tuner IC. The reference design connects to the motherboard through a 12-pin connector. The downconverted satellite signal from the LNB is supplied to an active, discrete loop-through, which splits the signal into two paths. One signal goes to the MAX2120 and the other provides an additional output from the STB.

5-channel (3 +V and 2 -V) hot-swap reference design

This article presents a five-channel hot-swap circuit that handles both positive and negative input voltages with sequential turn-on. The unique configuration allows two negative-voltage channels not protected by circuit breakers, in addition to three positive-voltage channels, to be controlled by a single MAX5927A positive-voltage hot-swap controller. The included test data verifies that the circuit meets the described load and power-sequencing requirements of the five channels.

WiBro reference design built with the MAX2837

The WiBro™ reference design is a complete RF front-end solution designed to meet requirements for the WiBro 2.3GHz to 2.4GHz mobile WMAN (Wireless Metropolitan Area Network) standard. This reference design uses the MAX2837 direct-conversion transceiver and demonstrates a complete WiBro single-band RF-to-baseband solution. It serves as a platform for designs in multiple form factors such as CardBus, miniPCI, and custom CPE modules. The design can be easily adapted for WiBro-only 3.3V laptop applications, or WiBro- only 5.0V CPE applications.

GPS USB Reference Design Using the MAX2769

The MAX2769 is a low-cost, single-conversion, low-IF frequency GPS receiver that provides 115dB cascaded gain and a 1.4dB cascaded NF. The MAX2769 GPS USB reference design, working together with the GeotateSM GPS software installed in a PC or laptop, forms a complete low-cost high-sensitivity GPS solution. The reference design provides high-precision position information with quick acquisition times. It demonstrates the excellent capabilities of the MAX2769 in a full GPS receiver design.

MAX2830 WLAN Reference Design

This reference design is a complete RF front-end solution designed to meet the WLAN IEEE® 802.11b/g standard. Using the MAX2830 RF transceiver, the design is capable of accommodating full range of 802.11g OFDM data rates (6, 9, 12, 18, 24, 36, 48, and 54Mbps) and 802.11b QPSK data rates (1, 2, 5.5, and 11Mbps). This solution offers high performance, small size, and low BOM cost.

MAX2769 GPS Reference Design

This reference design is a complete RF front-end solution for a GPS receiver using Maxim's MAX2769 GPS receiver chip. The MAX2769 is a low cost, single conversion, low IF GPS receiver that offers two integrated LNAs with different specifications, I/Q channel filters with variable bandwidth and order, and a digital IF output that supports 1-bit and 2-bit operation. This reference design offers high performance, small size, and low BOM cost.

DVB-T Receiver Reference Design for the MAX3580

The MAX3580 DVB-T reference design meets NorDig 1.0.3 and MBRAI requirements. This NIM design includes the MAX3580 direct-conversion tuner and a DVB-T demodulator/decoder. A discrete, active loop-through with low power consumption and low cost is included. Target applications include digital televisions, digital terrestrial set-tops, laptop televisions, automotive televisions, and USB peripherals.

1-Wire Bidirectional Level Translator (1.8V to 5V) Reference Design

Designers need open-drain logic to run at 1.8V at the 1-Wire master IO. Most 1-Wire slave devices cannot run at 1.8V. This application note presents an RD (reference design) of a circuit that translates from a 1.8V 1-Wire master to a 5V 1-Wire slave device. The RD is used for driving typical 1-Wire slave devices. The MAX3394E voltage-level translator is featured in the design.

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.