Datasheet LTC2492 (Analog Devices)

LTC2492 24-Bit 2-/4-Channel ΔS ADC with Easy Drive Input Current Cancellation
FeaTures DescripTion
n
Up to 2 Differential or 4 Single-Ended Inputs
The LTC®2492 is a 4-channel (2-channel differential), n
Easy Drive™ Technology Enables Rail-to-Rail
24-bit, No Latency ∆∑™ ADC with Easy Drive technology.
Inputs with Zero Differential Input Current
The patented sampling scheme eliminates dynamic input n
Directly Digitizes High Impedance Sensors with
current errors and the shortcomings of on-chip buffering
Full Accuracy
through automatic cancel ation of differential input current. n
600nVRMS Noise
This allows large external source impedances and rail-to- n
Integrated High Accuracy Temperature Sensor
rail input signals to be directly digitized while maintaining n
GND to VCC Input/Reference Common Mode Range
exceptional DC accuracy. n Programmable 50Hz, 60Hz, or Simultaneous The LTC2492 includes a high accuracy temperature sensor 50Hz/60Hz Rejection Mode and an integrated oscillator. This device can be configured n 2ppm INL, No Missing Codes to measure an external signal (from combinations of 4 n 1ppm Offset and 15ppm Full-Scale Error analog input channels operating in single-ended or dif- n 2x Speed Mode/Reduced Power Mode (15Hz Using ferential modes) or its internal temperature sensor. It can Internal Oscillator and 80µA at 7.5Hz Output) be programmed to reject line frequencies of 50Hz, 60Hz, n No Latency: Digital Filter Settles in a Single Cycle, or simultaneous 50Hz/60Hz and configured to double Even After a New Channel is Selected its output rate. The integrated temperature sensor offers n Single Supply 2.7V to 5.5V Operation (0.8mW) 1/30th°C resolution and 2°C absolute accuracy. n Internal Oscillator n Tiny DFN 4mm × 3mm Package The LTC2492 allows a wide common mode input range (0V to VCC), independent of the reference voltage. Any
applicaTions
combination of single-ended or differential inputs can be selected and the first conversion after a new channel n Direct Sensor Digitizer selection is valid. n Direct Temperature Measurement L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n Easy Drive and No Latency ΔS are trademarks of Linear Technology Corporation. All other Instrumentation trademarks are the property of their respective owners. n Industrial Process Control
Typical applicaTion Data Acquisition System with Temperature Compensation Absolute Temperature Error
2.7V TO 5.5V 5 4 10µF 0.1µF 3 CH0 VCC CH1 2 1 REF+ IN+ SDI 0 4-CHANNEL 24-BIT ∆∑ ADC SCK MUX 4-WIRE –1 WITH EASY-DRIVE SDO SPI INTERFACE CH2 IN– CS ABSOLUTE ERROR (°C) –2 CH3 REF– –3 COM –4 fO TEMPERATURE –5 OSC –55 –30 –5 20 45 70 95 120 SENSOR TEMPERATURE (°C) 2492 TA01a 2492 TA01b 2492fe For more information www.linear.com/LTC2492 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics (Normal Speed) Pin Configuration Electrical Characteristics (2x Speed) Converter Characteristics Analog Input and Reference Digital Inputs and Digital Outputs Power Requirements Digital Inputs and Digital Outputs Typical Performance Characteristics Pin Functions Functional Block Diagram Test Circuits Timing Diagrams Applications Information Package Description Revision History Typical Application Related Parts