Texas Instruments offers its ADS1257 30 kSPS, 4-channel, 24-bit ADC, PGA in a 5 mm x 5 mm VQFN package

     The Texas Instruments ADS1257 is a low-noise, 30 kSPS, 24-bit Delta Sigma (Delta Sigma) analog-to-digital converter (ADC) with an integrated multiplexer, input buffered, and programmable gain amplifier (PGA). This comes in a small 20-pin, 5mm x 5mm VQFN package. The combination of integration, high conversion and 24-bit resolution in a small package makes the device ideal for space-constrained applications.

     The input multiplexer accepts two differential or three single-ended input measurements. The sensor disconnects the circuit to verify continuity of the input connection to the ADC. The optional input buffer greatly increases the input impedance and, in many cases, eliminates the need for an external buffer. Buffer input voltage range includes. Low noise PGA provides gain from 1 to 64 to accommodate a wide range of inputs (from ±78 mV to ±5 V). Programmable digital filters optimize ADC resolution (up to 23-bit noise-free) and conversion rate (up to 30 kSPS). Digital filters provide single-cycle fixed conversions and suppress 50 Hz and 60 Hz interference signals.

     Spi compatible serial interfaces work with only three wires, simplifying connection to external controllers. The integrated calibration feature supports self and system correction of offset and gain errors for all PGA gain Settings. Two two-way digital I/Os pins control the external circuit.