LINEAR TECHNOLOGY LTC2499 Data Sheet / Manual

LTC2499

24-Bit 8-/16-Channel

DS ADC with Easy Drive Input Current Cancellation and I2C Interface

Fea Tures Descrip Tion ■ Up to Eight Differential or 16 Single-Ended Inputs

The LTC®2499 is a 16-channel (eight differential), 24-bit,

■ Easy Drive TM Technology Enables Rail-to-Rail

No Latency DSTM ADC with Easy Drive technology and a

Inputs with Zero Differential Input Current 2-wire, I2C interface. The patented sampling scheme elimi- ■ Directly Digitizes High Impedance Sensors with

nates dynamic input current errors and the shortcomings

Full Accuracy of on-chip buffering through automatic cancellation of ■ 2-Wire I2C Interface with 27 Addresses Plus One

differential input current. This allows large external source

Global Address for Synchronization impedances and rail-to-rail input signals to be directly ■ 600n V RMS Noise

digitized while maintaining exceptional DC accuracy.

■ Integrated High Accuracy Temperature Sensor

The LTC2499 includes a high accuracy, temperature

■ GND to VCC Input/Reference Common Mode Range

sensor and an integrated oscillator. This device can be

■ Programmable 50Hz, 60Hz or Simultaneous 50Hz/

configured to measure an external signal (from combi-

60Hz Rejection Mode

nations of 16 analog input channels operating in single-

■ 2ppm INL, No Missing Codes

ended or differential modes) or its internal temperature

■ 1ppm Offset and 15ppm Full-Scale Error

sensor. The integrated temperature sensor offers 1/30th

■ 2x Speed/Reduced Power Mode (15Hz Using Internal

°C resolution and 2°C absolute accuracy.

Oscillator and 80µA at 7.5Hz Output) AB SO LU TE RR OR (° C)

■ No Latency: Digital Filter Settles in a Single Cycle, The LTC2499 allows a wide common mode input range

Even After a New Channel Is Selected (0V to VCC), independent of the reference voltage. Any

■ Single Supply 2.7V to 5.5V Operation (0.8m W) combination of single-ended or differential inputs can ■ Internal Oscillator be selected and the first conversion, after a new channel ■ Tiny 5mm × 7mm QFN Package is selected, is valid. Access to the multiplexer output en-

ables optional external amplifiers to be shared between all applica Tions analog inputs and auto calibration continuously removes their associated offset and drift.

■ Direct Sensor Digitizer

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

■ Direct Temperature Measurement

No Latency DS and Easy Drive are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

■ Instrumentation

■ Industrial Process Control

Typical applica Tion

Integrated High Performance Temperature Sensor

Data Acquisition System with Temperature Compensation

2.7V TO 5.5V

CH0 VCCMUXOUT/ 10µF 0.1µF

CH1 ADCIN

REF+ 1.7k

CH7 IN+ 16-CHANNEL SDA CH8 24-BIT ∆Σ ADC 2-WIRE –1

WITH EASY DRIVE I2C INTERFACE

REF –3

TEMPERATURE FO

MUXOUT/ –5

SENSOR OSC

ADCIN –55 –30 –5

2499 TA01 TEMPERATURE (°C)

2499 TA02

2499fa