LTC2487 - 16-Bit 2-/4-Channel Delta Sigma ADC with PGA, Easy Drive and I2C Interface

The LTC2487 is a 4-channel (2 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 LTC2487 includes programmable gain, 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 1/2°C resolution and 2°C absolute accuracy. The LTC2487 can be configured to provide a programmable gain from 1 to 256 in 8 steps.

The LTC2487 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
Programmable Gain from 1 to 256
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
2x 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