FeaTures
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LTC2487
16-Bit 2-/4-Channel
DS
ADC
with PGA, Easy Drive and
I
2
C Interface
DescripTion
The LTC
®
2487 is a 4-channel (2 differential), 16-bit,
No Latency
DS™
ADC with Easy Drive technology and a
2-wire, I
2
C interface. The patented sampling scheme elimi-
nates 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 LTC2487 includes programmable gain, a high accuracy
temperature sensor and an integrated oscillator. This device
can be configured to measure an external signal (from com-
binations of 4 analog input channels operating in single-
ended or differential modes) or its internal temperature
sensor. The integrated temperature sensor offers 1/2°C
resolution and 2°C absolute accuracy. The LTC2487 can
be configured to provide a programmable gain from 1 to
256 in 8 steps.
The LTC2487 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
is selected, is valid. Access to the multiplexer output en-
ables optional external amplifiers to be shared between all
analog inputs and auto calibration continuously removes
their associated offset and drift.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
No Latency
DS
and Easy Drive are trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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Up to 2 Differential or 4 Single-Ended Inputs
Easy Drive
TM
Technology Enables Rail-to-Rail
Inputs with Zero Differential Input Current
Directly Digitizes High Impedance Sensors with
Full Accuracy
2-Wire I
2
C Interface with 9 Addresses Plus One
Global Address for Synchronization
600nV RMS Noise
Programmable Gain from 1 to 256
Integrated High Accuracy Temperature Sensor
GND to V
CC
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/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 4mm
×
3mm DFN Package
applicaTions
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Direct Sensor Digitizer
Direct Temperature Measurement
Instrumentation
Industrial Process Control
Typical applicaTion
Data Acquisition System with Temperature Compensation
2.7V TO 5.5V
CH0
CH1
IN
+
REF
+
16-BIT
∆Σ
ADC
WITH EASY-DRIVE
IN
–
REF
–
SDA
SCL
CA1
CA0
F
O
OSC
2487 TA01a
Built-In High Performance Temperature Sensor
5
4
ABSOLUTE ERROR (°C)
V
CC
0.1µF
10µF
3
2
1
0
–1
–2
–3
–4
–5
–55
–30
–5
20
45
70
TEMPERATURE (°C)
95
120
2487 TA02
1.7k
2-WIRE
I
2
C INTERFACE
9-PIN SELECTABLE
ADDRESSES
CH2
CH3
COM
4-CHANNEL
MUX
TEMPERATURE
SENSOR
2487fa
LINER [ LINEAR TECHNOLOGY ]
