LTC2488_15 Datasheet, PDF (1/30 Pages) Linear Technology – 16-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 _{600nV RMS Noise (0.02LSB Transition Noise)}
n _{GND to VCC Input/Reference Common Mode Range}
n _{Simultaneous 50Hz/60Hz Rejection}
n _{2ppm INL, No Missing Codes}
n _{1ppm Offset and 15ppm Full-Scale Error}
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 4mm × 3mm DFN Package}
APPLICATIONS
n _{Direct Sensor Digitizer}
n _{Direct Temperature Measurement}
n _{Instrumentation}
n _{Industrial Process Control}
LTC2488
16-Bit 2-/4-Channel ΔS
ADC with Easy Drive Input
Current Cancellation
DESCRIPTION
The LTC^®2488 is a 4-channel (2-channel differential),
16‑bit, No Latency DS™ 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 LTC2488 includes 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 differential modes. It automatically rejects line
frequencies of 50Hz and 60Hz simultaneously.
The LTC2488 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
No Latency DΣ and Easy Drive are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
TYPICAL APPLICATION
Data Acquisition System
2.7V TO 5.5V
CH0
CH1
4-CHANNEL
MUX
CH2
CH3
COM
V_CC
REF⁺
IN⁺
SDI
16-BIT ΔΣ ADC ^SCK
WITH EASY DRIVE SDO
IN^–
REF^–
CS
F_O
OSC
2488 TA01a
10µF
0.1µF
4-WIRE
SPI INTERFACE
Fullscale Error vs Source Resistance
80
V_CC = 5V
60
40
VVV^{RIINNE+–F}
=
=
=
5V
3.75V
1.25V
F_O = GND
20 ^{TA = 25°C}
0
C_IN = 1µF
–20
–40
–60
–80
1
10
100
1k
10k 100k
R_SOURCE (Ω)
2488 TA01b
For more information www.linear.com/LTC2488
2488fb
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