2 channel 24 bit ADC

Linear Technology's LTC2412 is a 24 bit no latency delta sigma ADC that offers two fully differential input channels and a differential reference input.

Low noise of 800 nVRMS provides 22.5 effective number of bits (ENOBs) over a ±2.5 V span and 16.9 ENOBs over a ±50 mV span, which eliminates the need for PGAs.

The wide input range handles sensor offsets and tare voltages, eliminating the need for front-end signal conditioning. This, together with the high resolution available, allows direct sensor connection for low cost, high accuracy data acquisition.

The no latency delta sigma architecture ensures single cycle digital filter settling even after a change in channels or input voltage step.

Transparent auto calibration, on every conversion, ensures stable output codes with a total unadjusted error of 3 ppm independent of time, temperature and supply. Operating from a single 2.7 to 5.5 V supply, the device consumes 200 µA and automatically shuts down to 4 µA between conversions benefiting portable or loop-powered applications.

It accepts two differential inputs, which are converted alternately without needing to be programmed. The full-scale input span is -0.5 to 0.5 VREF where the reference voltage can be anywhere between 0.1 V and VCC for flexible ratiometric and remote sensing configurations. An on-chip oscillator provides a selectable notch filter of 50 or 60 Hz with rejection better than 110 dB and eliminates external components.

An external clock source can be used for rejection of frequencies other than 50 or 60 Hz and the converter will adapt automatically.

It communicates through a 3 wire digital interface, which is compatible with the SPI protocol. The device is available in a 16 pin SSOP package, screened for industrial and commercial temperature ranges.