Texas Instruments ADS1257 is a low-noise, 30kSPS, 24-bit, delta-sigma (ΔΣ) analog-to-digital converter (ADC) with integrated multiplexer, input buffer, and programmable gain amplifier (PGA) ). Small 20-pin 5mm x 5mm VQFN package.
The combination of integration, high conversion rate, and compact package with 24-bit resolution make this device ideal for space-constrained applications.
The input multiplexer accepts two differential or three single-ended input measurements. The sensor disconnect circuit verifies the continuity of the input connection to the ADC. The optional input buffer greatly increases the input impedance, and in many cases, no external buffer is required. The buffer input voltage range includes AGND. The low noise PGA offers gains from 1 to 64 to accommodate a wide range of inputs (from ± 78mV to ± 5V). Programmable digital filters optimize ADC resolution (no noise up to 23 bits) and slew rate (up to 30kSPS). Digital filters provide single-cycle stable conversions and reject 50Hz and 60Hz interference signals.
The SPI-compatible serial interface requires only three wires to work, simplifying connections to external controllers. Integrated calibration supports self-correction and system correction of offset and gain errors for all PGA gain settings. Two bidirectional digital I / O pins control external circuits.
