LINEAR LTC2495 Data Sheet User Manual

LTC2495

16-Bit 8-/16-Channel

ΔΣ ADC with PGA, Easy Drive

and I2C Interface

FEATURES DESCRIPTION ■ Up to Eight Differential or 16 Single-Ended Inputs

The LTC®2495 is a 16-channel (eight differential), 16-bit,

■ Easy Drive TM Technology Enables Rail-to-Rail

No Latency ΔΣTM 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.

■ Programmable Gain from 1 to 256

The LTC2495 includes programmable gain, a high accuracy

■ Integrated High Accuracy Temperature Sensor

temperature sensor, and an integrated oscillator. This device

■ GND to VCC Input/Reference Common Mode Range

can be confi gured to measure an external signal (from com-

■ Programmable 50Hz, 60Hz, or Simultaneous 50Hz/ AB SO LU TE RR OR (° C)

binations of 16 analog input channels operating in single-

60Hz Rejection Mode

ended or differential modes) or its internal temperature

■ 2ppm INL, No Missing Codes

sensor. The integrated temperature sensor offers 1/2°C

■ 1ppm Offset and 15ppm Full-Scale Error

resolution and 2°C absolute accuracy. The LTC2495 can

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

be confi gured to provide a programmable gain from 1 to

Oscillator and 80µA at 7.5Hz Output)

256 in 8 steps.

■ No Latency: Digital Filter Settles in a Single Cycle,

Even After a New Channel is Selected The LTC2495 allows a wide common mode input range

■ Single Supply 2.7V to 5.5V Operation (0.8m W) (0V to VCC), independent of the reference voltage. Any ■ Internal Oscillator combination of single-ended or differential inputs can ■ Tiny 5mm × 7mm QFN Package be selected and the fi rst conversion, after a new channel

is selected, is valid. Access to the multiplexer output en-

APPLICATIONS ables optional external amplifi ers to be shared between all

analog inputs and auto calibration continuously removes

■ Direct Sensor Digitizer

their associated offset and drift.

■ Direct Temperature Measurement

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

■ Instrumentation

No Latency ∆Σ and Easy Drive are trademarks of Linear Technology Corporation. ■ Industrial Process Control All other trademarks are the property of their respective owners.

TYPICAL APPLICATION

Built-In High Performance Temperature Sensor

Data Acquisition System with Temperature Compensation

2.7V TO 5.5V

CH0 VCCMUXOUT/ 0.1µF 10µF

CH1 ADCIN

REF+ 1.7k

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

WITH EASY DRIVE I2C INTERFACE

SCL –2

CH15 –3

TEMPERATURE FO

MUXOUT/

SENSOR OSC –55 –30 –5

ADCIN

TEMPERATURE (°C)

2495 TA01 2495 TA02