LTC2493 - 24-Bit 2-/4-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation and I2C Interface

The LTC2493 is a 4-channel (2-channel differential), 24-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 LTC2493 includes a high accuracy temperature sensor and 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) or its internal temperature sensor. The integrated temperature sensor offers 1/30th°C resolution and 2°C absolute accuracy.

The LTC2493 allows a wide common mode input range (0V to VCC), 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.

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
600nVRMS Noise
Integrated High Accuracy Temperature Sensor
GND to VCC Input/Reference Common Mode Range
Programmable 50Hz, 60Hz or Simultaneous 50Hz/60Hz Rejection Mode
2ppm INL, No Missing Codes
1ppm Offset and 15ppm Full-Scale Error
2× Speed/Reduced Power Mode (15Hz Using Internal Oscillator and 80μA at 7.5Hz Output)
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