16-Bit 2-/4-Channel ΔΣ ADC with Easy Drive Input Current Cancellation

The LTC2488 is a 4-channel (2-channel 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 LTC2488 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 LTC2488 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 selection is valid.

Applications

* Direct Sensor Digitizer

* Direct Temperature Measurement

* Instrumentation

* Industrial Process Control

* 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

* 600nVRMS Noise (0.02LSB Transition Noise)

* GND to VCC 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