Features

• Up to 2 Differential or 4 Single-Ended Inputs
• Easy Drive™ Technology Enables Rail-to-Rail Inputs with Zero Differential Input Current
• Directly Digitizes High Impedance Sensors with Full Accuracy
• 2-Wire I²C Interface with 9 Addresses Plus One Global Address for Synchronization
• 600nV_RMS Noise (0.02LSB Transition Noise)
• GND to V_CC Input/Reference Common Mode Range
• Simultaneous 50Hz/60Hz Rejection
• 2ppm INL, No Missing Codes
• 1ppm Offset and 15ppm Full-Scale Error
• No Latency: Digital Filter Settles in a Single Cycle, Even After a New Channel is Selected
• Single Supply, 2.7V to 5.5V Operation (0.8mW)
• Internal Oscillator
• Tiny 4mm × 3mm DFN Package

Typical Application

Description

The LTC2489 is a 4-channel (2-channel differential), 16-bit, No Latency ΔΣ™ ADC with Easy Drive technology and a 2-wire, I²C interface. The patented sampling scheme eliminates dynamic input current errors and the shortcomings of on-chip buffering through automatic cancellation of differential input current. This allows large external source impedances and rail-to-rail input signals to be directly digitized while maintaining exceptional DC accuracy.

The LTC2489 includes an integrated oscillator. This device can be configured to measure an external signal from combinations of 4 analog input channels operating in single ended or differential modes. It automatically rejects line frequencies of 50Hz and 60Hz simultaneously.

The LTC2489 allows a wide, common mode input range (0V to V_CC), independent of the reference voltage. Any combination of single-ended or differential inputs can be selected and the first conversion, after a new channel is selected, is valid. Access to the multiplexer output enables optional external amplifiers to be shared between all analog inputs and auto calibration continuously removes their associated offset and drift.