Linear Technology LTC2421IMS#PBF

Description
The LTC2421/LTC2422 are 1- and 2-channel 20-bit analog-to-digital converters (ADCs) with an integrated oscillator, 8ppm INL, and 1.2ppm RMS noise. These devices use delta-sigma technology and a new digital filter architecture that settles in a single cycle, eliminating latency found in conventional AΣ converters. They accept an external reference voltage from 0.1V to Vcc and have an extended input conversion range of -12.5% VREF to 112.5% VREF. The LTC2421/LTC2422 communicate through a 2- or 3-wire digital interface that is compatible with SPI and MICROWIRE™ protocols.

Features
1-/2-Channel 20-Bit μPower No Latency ATM ADCs in MSOP-10
Single Supply 2.7V to 5.5V Operation
Low Supply Current (200μA) and Auto Shutdown
Automatic Channel Selection (Ping-Pong) (LTC2422)
No Latency: Digital Filter Settles in a Single Conversion Cycle
8ppm INL, No Missing Codes
4ppm Full-Scale Error
0.5ppm Offset
1.2ppm Noise
Zero Scale and Full Scale Set for Reference and Ground Sensing
Internal Oscillator-No External Components Required
110dB Min, 50Hz/60Hz Notch Filter
Reference Input Voltage: 0.1V to Vcc
Live Zero-Extended Input Range Accommodates 12.5% Overrange and Underrange
Pin Compatible with LTC2401/LTC2402

Applications
Weight Scales
Direct Temperature Measurement
Gas Analyzers
Strain Gauge Transducers
Instrumentation
Data Acquisition
Industrial Process Control