The LTC2420 is a micropower 20-bit A/D converter with an integrated oscillator, 8ppm INL and 1.2ppm RMS noise that operates from 2.7V to 5.5V. It uses delta-sigma technology and provides a digital filter that settles in a single cycle for multiplexed applications. Through a single pin, the LTC2420 can be configured for better than 110dB rejection at 50Hz or 60Hz ±2%, or it can be driven by an external oscillator for a user-defined rejection frequency in the range 1Hz to 800Hz. The internal oscillator requires no external frequency setting components. The converter accepts any external reference voltage from 0.1V to VCC. With its extended input conversion range of -12.5% VREF to 112.5% VREF, the LTC2420 smoothly resolves the offset and overrange problems of preceding sensors or signal conditioning circuits. The LTC2420 communicates through a flexible 3-wire digital interface which is compatible with SPI and MICROWIRE™ protocols.
