The LTC2435/2435-1 are 2.7V to 5.5V micropower 20-bit differential analog to digital converters with integrated oscillator, 3ppm INL and 0.8ppm RMS noise. They use delta-sigma technology and provide single cycle settling time for multiplexed applications. Through a single pin, the LTC2435 can be configured for better than 110dB input differential mode rejection at 50Hz or 60Hz 2%, or it can be driven by an external oscillator for a user defined rejection frequency. The LTC2435-1 can be configured for better than 87dB input differential mode rejection over the range of 49Hz to 61.2Hz (50Hz and 60Hz 2% simultaneously). The internal oscillator requires no external frequency setting components.