SAR ADCs allow ±12V input range

Texas Instruments Inc. has rolled out two bipolar, 12bit, 1MSPS successive approximation register (SAR) analog-to-digital converters (ADCs) for programmable logic control (PLC) and data acquisition.

The 4-channel ADS8634 and 8-channel ADS8638 offer wide temperature range available for demanding industrial measurement applications up to 125°C and are characterised over the extended industrial temperature range. They also allow an input range of ±12V, an improvement of 20 percent over the competition, when used with an external reference.

Both the ADS8634 and ADS8638 have per-channel software-selectable input ranges support ±12V, ±10V, ±5V, ±2.5V, 0-5V and 0-10V, providing a single-chip solution for a range of inputs, while enabling designers to interface to a variety of sensors with a single ADC.

The devices' 1MSPS sampling rate is a 4x improvement from previous generation products of the same category. The digital interfaces of the ADS8634 and ADS8638 support 1.8–5V hosts without additional level-shifting circuitry. They both have integrated reference and temperature sensor reduces system cost and complexity. The addition of dual-alarm threshold logic per channel and alarm output minimizes the number of host accesses required in monitoring applications.

TI offers a variety of tools and support to speed development with the ADS8634 and ADS8638, including an IBIS model, anti-aliasing filter tool for data converters, and an op amp-to-ADC circuit topography calculator.

A performance development kit, including all circuitry, software and source code, is also available to evaluate the performance of both parts. The ADS8638EVM-PDK enables complete ADC performance evaluation via ADCPro, a modular software system for evaluating ADCs without expensive logic analyzers and complex analysis routines. The ADS8638EVM-PDK can be purchased today for a suggested retail price of $199.

The ADS8634 and ADS8638 are available now in a 4 x 4mm QFN package. The ADS8634 can be purchased for a suggested retail price of $2.85 for 1,000 units, and the ADS8638 is available for a suggested retail price of $3.25 for 1,000 units.