
LTC2492
1
2492fd
TEMPERATURE (°C)
–55
–30
– 5
ABSOLUTE
ERROR
(°C)
5
4
3
2
1
–4
–3
–2
–1
0
120
95
70
45
20
2492 TA01b
–5
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
24-Bit 2-/4-Channel
ΔΣ
ADC with Easy Drive Input
Current Cancellation
The LTC2492 is a 4-channel (2-channel differential),
24-bit, No Latency Δ∑ 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 congured
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 congured 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 VCC), independent of the reference voltage. Any
combination of single-ended or differential inputs can
be selected and the rst 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
ΔΣ are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
Data Acquisition System with Temperature Compensation
■
Up to 2 Differential or 4 Single-Ended Inputs
■
Easy Drive Technology Enables Rail-to-Rail
Inputs with Zero Differential Input Current
■
Directly Digitizes High Impedance Sensors with
Full Accuracy
■
600nVRMS Noise
■
Integrated High Accuracy Temperature Sensor
■
GND to VCC Input/Reference Common Mode Range
■
Programmable 50Hz, 60Hz, or Simultaneous
50Hz/60Hz Rejection Mode
■
2ppm INL, No Missing Codes
■
1ppm Offset and 15ppm Full-Scale Error
■
2x Speed Mode/Reduced Power Mode (15Hz Using
Internal Oscillator and 80μA at 7.5Hz Output)
■
No Latency: Digital Filter Settles in a Single Cycle,
Even After a New Channel is Selected
■
Single Supply 2.7V to 5.5V Operation (0.8mW)
■
Internal Oscillator
■
Tiny DFN 4mm
× 3mm Package
■
Direct Sensor Digitizer
■
Direct Temperature Measurement
■
Instrumentation
■
Industrial Process Control
Absolute Temperature Error
SDI
SCK
SDO
CS
fO
REF+
VCC
2.7V TO 5.5V
10μF
COM
REF –
24-BIT Δ∑ ADC
WITH EASY-DRIVE
4-CHANNEL
MUX
TEMPERATURE
SENSOR
IN+
IN–
2492 TA01a
4-WIRE
SPI INTERFACE
CH0
CH1
CH3
CH2
0.1μF
OSC