Datasheet LTC2499 (Analog Devices)

LTC2499 24-Bit 8-/16-Channel DS ADC with Easy Drive Input Current Cancellation and I2C Interface
Features Description
n
Up to Eight Differential or 16 Single-Ended Inputs
The LTC®2499 is a 16-channel (eight differential), 24-bit, n
Easy Drive™ Technology Enables Rail-to-Rail
No Latency DS™ ADC with Easy Drive technology and a
Inputs with Zero Differential Input Current
2-wire, I2C interface. The patented sampling scheme elimi- n
Directly Digitizes High Impedance Sensors with
nates 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
Integrated High Accuracy Temperature Sensor
The LTC2499 includes a high accuracy, temperature n
GND to VCC Input/Reference Common Mode Range
sensor and an integrated oscillator. This device can be n Programmable 50Hz, 60Hz or Simultaneous configured to measure an external signal (from combi- 50Hz/60Hz Rejection Mode nations of 16 analog input channels operating in single- n 2ppm INL, No Missing Codes ended or differential modes) or its internal temperature n 1ppm Offset and 15ppm Full-Scale Error sensor. The integrated temperature sensor offers 1/30th°C n 2x Speed/Reduced Power Mode (15Hz Using Internal resolution and 2°C absolute accuracy. Oscillator and 80µA at 7.5Hz Output) n The LTC2499 allows a wide common mode input range No Latency: Digital Filter Settles in a Single Cycle, (0V to V Even After a New Channel Is Selected CC), independent of the reference voltage. Any n combination of single-ended or differential inputs can Single Supply 2.7V to 5.5V Operation (0.8mW) n be selected and the first conversion, after a new channel Internal Oscillator n is selected, is valid. Access to the multiplexer output en- Tiny 5mm × 7mm QFN Package ables optional external amplifiers to be shared between all
applications
analog inputs and auto calibration continuously removes their associated offset and drift. n Direct Sensor Digitizer L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n Direct Temperature Measurement No Latency ∆∑ and Easy Drive are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Instrumentation n Industrial Process Control
typical application Integrated High Performance Temperature Sensor Data Acquisition System with Temperature Compensation
5 2.7V TO 5.5V 4 3 CH0 MUXOUT/ VCC 10µF 0.1µF CH1 ADCIN 2 • REF+ • 1 • IN+ CH7 1.7k 16-CHANNEL 24-BIT ∆Σ ADC 0 CH8 MUX WITH EASY DRIVE SDA 2-WIRE • –1 • IN– SCL I2C INTERFACE • CH15 REF– ABSOLUTE ERROR (°C) –2 COM –3 fO TEMPERATURE MUXOUT/ –4 OSC SENSOR ADCIN –5 2499 TA01 –55 –30 –5 20 45 70 95 120 TEMPERATURE (°C) 2499 TA02 2499fe For more information www.linear.com/LTC2499 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