SAR ADC with SPICE model claims industry first

May 23, 2012 // By Jean-Pierre Joosting
Texas Instruments has introduced a successive-approximation-register (SAR) analog-to-digital converter (ADC) with a downloadable TINA-TI SPICE model, enabling system designers to simulate and characterize the full analog signal chain in software for the first time.

The model is available for the latest 12-bit, 1-MSPS, 8-channel ADS8028, a highly-integrated SAR ADC featuring a low-drift internal voltage reference, wide external analog voltage reference range, wide analog and digital supply ranges, and an internal temperature sensor.

Designers could previously only simulate, model and test up to the SAR ADC, requiring them to invest time and resources building the ADC circuit in hardware. With a downloadable TINA-TI SPICE model available for all new SAR ADCs, designers will be able to fully verify ADC driving circuitry, enabling them to speed product development.

Tools to simulate and evaluate quickly comprise the TINA-TI reference design and product evaluation module (EVM) which include the OPA836 driver amplifier for fast software simulation and hardware evaluation.

A high level of integration reduces board space and bill of materials The ADS8028 integrates an internal 2.5-V reference, +1° Celsius accurate temperature sensor and internal multiplexer with sequencer; it also eliminates the need for an external decoupling capacitor.

Wide supply ranges provide greater power supply flexibility — a 3x wider analog supply range of 2.7 V to 5.25 V, 80-percent wider digital supply range of 1.65 V to 5.25 V and 2.5x wider external reference range of 1 V to 5 V, compared to the competition.

The ADS8028 consumes a maximum of 36 µW in power-down mode across a wide operating temperature range of -40 C to 125 C in a small 4-mm x 4-mm package to support battery-powered, space-constrained designs.

In addition to the TINA-TI SPICE model, an IBIS model is available to verify board signal integrity requirements.