16-Bit 8-/16-Channel ΔΣ ADC with PGA and Easy Drive Input Current Cancellation

The LTC2494 is a 16-channel (8-differential), 16-bit, No Latency ΔΣ™ ADC with Easy Drive technology. 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 LTC2494 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 16 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 LTC2494 can be configured to provide a programmable gain from 1 to 256 in 8 steps.

The LTC2494 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.

Applications

* Direct Sensor Digitizer

* Direct Temperature Measurement

* Instrumentation

* Industrial Process Control

* Up to 8 Differential or 16 Single-Ended Inputs

* Easy Drive™ Technology Enables Rail-to-Rail Inputs with Zero Differential Input Current

* Directly Digitizes High Impedance Sensors with Full Accuracy

* 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 Mode/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

* Internal Oscillator

* Tiny 5mm × 7mm QFN Package