Linear Technology DC951A - LTC2481 16-bit, Delta-Sigma ADC (req DC590) DC951A DC951A Fiche De Données

Codes de produits
DC951A
Page de 40
LTC2481
1
2481fc
 TYPICAL APPLICATION 
 FEATURES
 DESCRIPTION
16-Bit 
ΔΣ ADC with Easy Drive 
Input Current Cancellation 
and I
2
C Interface
The LTC
®
2481 combines a 16-bit plus sign No Latency 
ΔΣ
 
analog-to-digital converter with patented Easy Drive 
technology and I
2
C digital interface. 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 input signals, with rail-to-
rail input range to be directly digitized while maintaining 
exceptional DC accuracy. 
The LTC2481 includes on-chip programmable gain, a 
temperature sensor and an oscillator. The LTC2481 can 
be confi gured through an I
2
C interface to provide a pro-
grammable gain from 1 to 256 in 8 steps, to digitize an 
external signal or internal temperature sensor, reject line 
frequencies (50Hz, 60Hz or simultaneous 50Hz/60Hz) as 
well as a 2x speed-up mode.
The LTC2481 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 LTC2481 includes an on-chip trimmed oscil-
lator eliminating the need for external crystals or oscil-
lators. Absolute accuracy and low drift are automatically 
maintained through continuous, transparent, offset and 
full-scale calibration.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and 
No Latency Δ∑ and Easy Drive are trademarks of Linear Technology Corporation. 
All other trademarks are the property of their respective owners. Patents Pending.
+FS Error vs R
SOURCE
 at IN
+
 and IN
  APPLICATIONS
n
  Easy Drive
 Technology Enables Rail-to-Rail Inputs 
with Zero Differential Input Current
n
  Directly Digitizes High Impedance Sensors with 
Full Accuracy
n
  Programmable Gain from 1 to 256
n
  Integrated Temperature Sensor
n
  GND to V
CC
 Input/Reference Common Mode Range
n
 2-Wire I
2
C Interface
n
  Programmable 50Hz, 60Hz or Simultaneous 
50Hz/60Hz Rejection Mode
n
  2ppm (0.25LSB) INL, No Missing Codes
n
  1ppm Offset and 15ppm Full-Scale Error
n
  Selectable 2x Speed Mode 
n
  No Latency: Digital Filter Settles in a Single Cycle
n
  Single Supply 2.7V to 5.5V Operation
n
 Internal Oscillator
n
  Six Addresses Available and One Global Address for
Synchronization
n
  Available in a Tiny (3mm 
× 3mm) 10-Lead DFN Package
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
LTC2481
V
IN
+
REF
+
V
CC
V
CC
GND
V
IN
1μF
SDA
2-WIRE
I
2
C INTERFACE
0.1μF
0.1μF
10k
I
DIFF
 = 0
10k
CA0/f
0
2481 TA01a
CA1
SCL
6 ADDRESSES
REF
SENSE
R
SOURCE
 (Ω)
1
+FS ERROR (ppm)
–20
0
20
1k
100k
2481 TA01b
–40
–60
–80
10
100
10k
40
60
80
V
CC
 = 5V
V
REF
 = 5V
V
IN
+
 = 3.75V
V
IN
 = 1.25V
f
O
 = GND
T
A
 = 25°C
C
IN
 = 1μF