Datasheet LTC2495 (Analog Devices)

LTC2495 16-Bit 8-/16-Channel DS ADC with PGA, Easy Drive and I2C Interface
Features Description
n
Up to Eight Differential or 16 Single-Ended Inputs
The LTC®2495 is a 16-channel (eight differential), 16-bit, n
Easy DriveTM 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 elim- n
Directly Digitizes High Impedance Sensors with
inates dynamic input current errors and the shortcomings
Full Accuracy
of on-chip buffering through automatic cancellation of n
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 n
600nV RMS Noise
digitized while maintaining exceptional DC accuracy. n
Programmable Gain from 1 to 256
The LTC2495 includes programmable gain, a high accuracy n
Integrated High Accuracy Temperature Sensor
temperature sensor, and an integrated oscillator. This device n
GND to VCC Input/Reference Common Mode Range
can be configured to measure an external signal (from com- n Programmable 50Hz, 60Hz, or Simultaneous binations of 16 analog input channels operating in single- 50Hz/60Hz Rejection Mode ended or differential modes) or its internal temperature n 2ppm INL, No Missing Codes sensor. The integrated temperature sensor offers 1/2°C n 1ppm Offset and 15ppm Full-Scale Error resolution and 2°C absolute accuracy. The LTC2495 can n 2x Speed/Reduced Power Mode (15Hz Using Internal be configured to provide a programmable gain from 1 to Oscillator and 80µA at 7.5Hz Output) 256 in 8 steps. n 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 n Single Supply 2.7V to 5.5V Operation (0.8mW) (0V to VCC), independent of the reference voltage. Any n Internal Oscillator combination of single-ended or differential inputs can n Tiny 5mm × 7mm QFN Package be selected and the first conversion, after a new channel
applications
is selected, is valid. Access to the multiplexer output en- ables optional external amplifiers to be shared between all n analog inputs and auto calibration continuously removes Direct Sensor Digitizer n their associated offset and drift. Direct Temperature Measurement L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n Instrumentation No Latency DS and Easy Drive are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Industrial Process Control
typical application Built-In High Performance Temperature Sensor Data Acquisition System with Temperature Compensation
5 2.7V TO 5.5V 4 3 CH0 MUXOUT/ VCC 0.1µF 10µF 2 CH1 ADCIN • REF+ 1 • • IN+ CH7 1.7k 16-CHANNEL 0 16-BIT ∆Σ ADC CH8 MUX WITH EASY DRIVE SDA 2-WIRE –1 • • IN– SCL I2C INTERFACE • ABSOLUTE ERROR (°C) –2 CH15 REF– –3 COM fO –4 TEMPERATURE MUXOUT/ OSC SENSOR –5 ADCIN –55 –30 –5 20 45 70 95 120 2495 TA01 TEMPERATURE (°C) 2495 TA02 2495fe For more information www.linear.com/LTC2495 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration order information Electrical Characteristics (Normal Speed) Electrical Characteristics (2x Speed) Converter Characteristics Analog Input and Reference I2C Inputs And Digital Outputs Power Requirements Digital Inputs And Digital Outputs I2C Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Applications Information Package Description Revision History Related Parts