LTC2492_15 Datasheet, PDF (1/38 Pages) Linear Technology – 24-Bit 2-/4-Channel ADC with Easy Drive Input Current Cancellation

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