Datasheet LTC2487 (Analog Devices)

LTC2487 16-Bit 2-/4-Channel DS ADC with PGA, Easy Drive and I2C Interface
FEATURES DESCRIPTION
n
Up to 2 Differential or 4 Single-Ended Inputs
The LTC®2487 is a 4-channel (2 differential), 16-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 9 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 LTC2487 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 4 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 LTC2487 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 LTC2487 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 4mm × 3mm DFN Package be selected and the first conversion, after a new channel is selected, is valid. Access to the multiplexer output en-
APPLICATIONS
ables optional external amplifiers to be shared between all analog inputs and auto calibration continuously removes n Direct Sensor Digitizer their associated offset and drift. n Direct Temperature Measurement All registered trademarks and trademarks are the property of their respective owners. n Instrumentation 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 V 0.1µF 10µF CC CH1 2 REF+ 1 IN+ 1.7k 0 4-CHANNEL 16-BIT ∆Σ ADC SDA MUX 2-WIRE CH2 WITH EASY-DRIVE –1 SCL I2C INTERFACE CH3 IN– ABSOLUTE ERROR (°C) –2 COM REF– CA1 9-PIN SELECTABLE –3 CA0 ADDRESSES –4 TEMPERATURE fO SENSOR OSC –5–55 –30 –5 20 45 70 95 120 2487 TA01a TEMPERATURE (°C) 2487 TA02 2487fg For more information www.linear.com/LTC2487 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration 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 Functional Block Diagram Applications Information Package Description Revision History Typical Application Related Parts