Datasheet LTC2486 (Analog Devices)

LTC2486 16-Bit 2-/4-Channel ΔS ADC with PGA and Easy Drive Input Current Cancellation
FEATURES DESCRIPTION
n
Up to 2 Differential or 4 Single-Ended Inputs
The LTC®2486 is a 4-channel (2-channel differential), n
Easy Drive Technology Enables Rail-to-Rail Inputs
16-bit, No Latency ΔS™ ADC with Easy Drive™ technology.
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
600nV RMS Noise
This allows large external source impedances and rail-to- n
Programmable Gain from 1 to 256
rail input signals to be directly digitized while maintaining n
Integrated High Accuracy Temperature Sensor
exceptional DC accuracy. n
GND to VCC Input/Reference Common Mode Range
The LTC2486 includes programmable gain, a high accuracy n Programmable 50Hz, 60Hz, or Simultaneous temperature sensor, and an integrated oscillator. This de- 50Hz/60Hz Rejection Mode vice can be configured to measure an external signal (from n 2ppm INL, No Missing Codes combinations of 4 analog input channels operating in single n 1ppm Offset and 15ppm Full-Scale Error ended or differential modes) or its internal temperature n 2x Speed Mode/Reduced Power Mode (15Hz Using sensor. It can be programmed to reject line frequencies of Internal Oscillator and 80µA at 7.5Hz Output) 50Hz, 60Hz, or simultaneous 50Hz/60Hz, provide a pro- n No Latency: Digital Filter Settles in a Single Cycle, grammable gain from 1 to 256 in 8 steps, and configured to Even After a New Channel is Selected double its output rate. The integrated temperature sensor n Single Supply 2.7V to 5.5V Operation (0.8mW) offers 1/2°C resolution and 2°C absolute accuracy. n Internal Oscillator n Tiny 4mm × 3mm DFN Package The LTC2486 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 of Linear n Technology Corporation. No Latency ΔS and Easy Drive are trademarks of Linear Technology Instrumentation Corporation. All other 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 0.1µF 10µF CH0 VCC 3 CH1 2 REF+ 1 IN+ SDI 4-CHANNEL 16-BIT ∆Σ ADC SCK 0 MUX 4-WIRE WITH EASY-DRIVE SDO SPI INTERFACE CH2 –1 IN– CS CH3 REF– ABSOLUTE ERROR (°C) –2 COM –3 fO –4 TEMPERATURE SENSOR OSC –5–55 –30 –5 20 45 70 95 120 2486 TA01a TEMPERATURE (°C) 2486 TA01b 2486fe For more information www.linear.com/LTC2486 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics (Normal Speed) Electrical Characteristics (2x Speed) Converter Characteristics Analog Input and Reference Digital Inputs and Digital Outputs Power Requirements Typical Performance Characteristics Pin Functions Functional Block Diagram Test Circuits Timing Diagrams Applications Information Package Description Revision History Typical Application Related Parts