The LTC2421/LTC2422 are 1- and 2-channel 2.7V to 5.5V micropower 20-bit analog-to-digital converters with an integrated oscillator, 8ppm INL and 1.2ppm RMS noise. These ultrasmall devices use delta-sigma technology and a new digital filter architecture that settles in a single cycle. This eliminates the latency found in conventional ∆Σ converters and simplifies multiplexed applications.Through a single pin, the LTC2421/LTC2422 can be configured for better than 110dB rejection at 50Hz or 60Hz ±2%, or can be driven by an external oscillator for a user defined rejection frequency in the range 1Hz to 120Hz. The internal oscillator requires no external frequency setting components.These converters accept an external reference voltage from 0.1V to VCC. With an extended input conversion range of –12.5% VREFto 112.5% VREF(VREF= FSSET– ZSSET), the LTC2421/LTC2422 smoothly resolve the offset and overrange problems of preceding sensors or signal conditioning circuits.The LTC2421/LTC2422 communicate through a 2- or 3-wire digital interface that is compatible with SPI and MICROWIRE™protocols.ApplicationsWeight ScalesDirect Temperature MeasurementGas AnalyzersStrain Gauge TransducersInstrumentationData AcquisitionIndustrial Process Control