Low-Noise Two-Channel ADC Possesses Fully Differential Input

Two fully differential input channels, along with a differential reference input, highlight the LTC2412 24-bit no-latency delta-sigma analog-to-digital converter (ADC). Low noise of 800 nV_RMS provides 22.5 effective number of bits (ENOBs) over a ±2.5-V span and 16.9 ENOBs over a ±50-mV span. The ADC's architecture ensures single-cycle digital filter settling even after a change in channels or input voltage step. Operating from a single 2.7- to 5.5-V supply, the LTC2412 consumes only 200 mA of supply current and automatically shuts down to 4 mA between conversions. An on-chip oscillator provides a selectable notch filter of 50 to 60 Hz, with rejection better than 110 dB. The ADC communicates through a three-wire digital serial-peripheral-interface-compatible interface. The LTC2412, offered in a 16-pin SSOP package, starts at $4.75 each in 1000-unit lots.