High-resolution resistive sensing conditioner mixes performance and precision

June 24, 2015 // By Graham Prophet
TI's one-chip solution integrates 24-bit ADCs, 14-bit DAC, programmable core, power management and multiple output interfaces in a small form factor

Texas Instruments positions its PGA900 as the highest-available resolution resistive sensing signal conditioner, enabling fast and precise 24-bit measurement of conditions such as pressure, strain, flow or liquid levels. The signal conditioner has a programmable core, enabling flexible linearisation and temperature compensation for resistive bridge sensing applications.

The PGA900 integrates two low-noise 24-bit analogue-to-digital converters, a 14-bit digital-to-analogue converter, and a variety of output interfaces, including analogue voltage, 4-20 mA current loop, SPI, I ²C, UART, and one-wire interface (OWI). The PGA900’s integrated power management accepts external power supply voltages from 3.3 to 30V.

Features include low-drift voltage reference of 10 ppm/°C, maximum, enabling high accuracy across the -40°C to 150°C operating temperature range; User-programmable temperature and nonlinearity compensation algorithms; Integrated ARM Cortex-M0 core that allows developers to use proprietary temperature and nonlinearity compensation algorithms to differentiate their end products.

The One-wire interface allows communication, configuration and calibration through the power supply pin without using additional lines; and integrated power management circuitry accepts input voltages ranging from 3.3 V to 30 V to simplify the design and provide reliability.

The PGA900 evaluation module (EVM) is available for $249. PGA900 example software and the user's guide, as well as the PSpice and TINA-TI Spice and TINA-TI models can be downloaded.

Texas Instruments; www.ti.com/PGA900-pr