ADCs eliminate typical design trade-offs

21st July 2015

Siobhan O'Gorman

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Datasheet Whitepaper

A pair of 32-bit delta-sigma ADCs that combine high resolution, low noise and integrated fault detection, eliminating many of the performance and features trade-offs typically associated with device evaluation and selection, have been introduced by Texas Instruments. The highly integrated, sensor-ready ADS1262 and ADS1263 also remove the need for external components that increase system cost and degrade noise and drift performance.

Until now, system designers who needed a high-resolution ADC had to sacrifice other desired specifications, such as low noise or low offset drift, as well as several integrated features. The ADS1262 and ADS1263 eliminate these trade-offs by providing 32-bit resolution, along with integration, fault-detection features, a fast data rate and wide temperature range, to help maximise the performance of PLCs, industrial automation equipment and sensor-measurement applications.

High resolution of 32-bits and low noise of 7nVRMS at 2.5SPS enable measurement of the smallest signals, which is essential for bridge applications where typical full-scale signals are 10mV or less. Offset error drift is also 80% lower than competitive solutions, ensuring measurement stability over the entire temperature range. The ADS1262 integrates a PGA, 2.5V reference, oscillator, level shifter, temperature sensor, dual-excitation current sources and eight GPIO pins. The ADS1263 adds an auxiliary 24-bit delta-sigma ADC for systems needing parallel main-channel conversions, sensor-temperature compensation or sensor diagnostics. Features such as internal signal-chain monitoring, data-error detection, sensor-burnout detection and a test DAC provide the internal and external fault detection and diagnostics necessary for high-reliability systems. A maximum output data rate of 38kSPS enables the ADCs to be used in high-data-throughput industrial applications. The operating temperature range of -40 to +125°C is 20°C wider than competing products.

TI offers a range of support tools for the ADS1262 and ADS1263 to speed time-to-market, including a TI Designs reference design for high resolution, low drift precision weigh scale measurements using AC bridge excitation.

The ADS1262 and ADS1263 provide complete support suites that are available for system designers, including samples, an IBIS model, an Excel calculator tool that aids in device configuration, and Performance Development Kits (PDKs). The ADS1262EVM-PDK and the ADS1263EVM-PDK are available for $199 from the TI store and authorised distributors.

Support for the ADS1262 and ADS1263 is available on the Precision Data Converters forum in the TI E2E Community, where engineers can search for solutions, get help, share knowledge, and solve problems with fellow engineers and TI experts.

Engineers designing with data converters like the ADS1262 and ADS1263 can also visit TI’s new Data Converter Learning Center to find how-to design resources organised by topic, such as delta-sigma ADC basics, ADC noise analysis and filtering, and driving ADCs.

The ADS1262 is available today in a 9.7x6.4mm TSSOP for $9.10. The ADS1263 is also available in a 9.7x6.4mm TSSOP for $12.65. All pricing is in 1,000-unit quantities.