LTC2482 Datasheet, PDF (1/32 Pages) Linear Technology – 16-Bit ΔΣ ADC with Easy Drive Input Current Cancellation

FEATURES
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, Independent of VREF}
n _{Operates with a Reference as Low as 100mV with}
16-Bit Resolution
n _{GND to VCC Input/Reference Common Mode Range}
n _{Simultaneous 50Hz/60Hz Rejection Mode}
n _{2ppm INL, No Missing Codes}
n _{1ppm Offset and 15ppm Total Unadjusted Error}
n _{No Latency: Digital Filter Settles in a Single Cycle}
n _{Single Supply 2.7V to 5.5V Operation}
n _{Internal Oscillator}
n _{Available in a Tiny (3mm × 3mm) 10-Lead}
DFN Package
APPLICATIONS
n _{Direct Sensor Digitizer}
n _{Weight Scales}
n _{Direct Temperature Measurement}
n _{Strain Gauge Transducers}
n _{Instrumentation}
n _{Industrial Process Control}
n _{DVMs and Meters}
LTC2482
16-Bit ΔΣ ADC with
Easy Drive Input Current
Cancellation
DESCRIPTION
The LTC^®2482 combines a 16-bit plus sign No Latency
ΔΣ™ analog-to-digital converter with patented Easy Drive™
technology. The patented sampling scheme eliminates
dynamic input current errors and the shortcomings of
on-chip buffering through automatic cancellation of dif-
ferential input current. This allows large external source
impedances and input signals with rail-to-rail input range
to be directly digitized while maintaining exceptional DC
accuracy.
The LTC2482 allows a wide common mode input range (0V
to V_CC) independent of the reference voltage. The reference
can be as low as 100mV or can be tied directly to V_CC.
The noise level is 600nV RMS independent of V_REF. This
allows direct digitization of low level signals with 16-bit
accuracy. The LTC2482 includes an on-chip trimmed
oscillator, eliminating the need for external crystals or
oscillators and provides 87dB rejection of 50Hz and 60Hz
line frequency noise. Absolute accuracy and low drift are
automatically maintained through continuous, transparent,
offset and full-scale calibration.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
No Latency ΔΣ and Easy Drive are trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Patent pending.
TYPICAL APPLICATION
V_CC
1μF
10k
SENSE
10k
I_DIFF = 0
1μF
V_IN+ ^VREF
V_CC
LTC2482
V_IN–
GND
f_O
SDO
SCK _3-WIRE
CS ^{SPI INTERFACE}
2482 TA01
+FS Error vs R_SOURCE at IN⁺ and IN^–
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)
2482 TA02
2482fb
1