Datasheet

LTC2412
1
2412f
The LTC
®
2412 is a 2-channel differential input micropower
24-bit No Latency ∆Σ
TM
analog-to-digital converter with
an integrated oscillator. It provides 2ppm INL and 0.16ppm
RMS noise over the entire supply range. The two differen-
tial channels are converted alternately with channel ID
included in the conversion results. It uses delta-sigma
technology and provides single conversion settling of the
digital filter. Through a single pin, the LTC2412 can be
configured for better than 110dB input differential mode
rejection at 50Hz or 60Hz ±2%, or it can be driven by an
external oscillator for a user defined rejection frequency.
The internal oscillator requires no external frequency
setting components.
The converter accepts any external differential reference
voltage from 0.1V to V
CC
for flexible ratiometric and
remote sensing measurement configurations. The full-
scale differential input range is from –0.5V
REF
to 0.5V
REF
.
The reference common mode voltage, V
REFCM
, and the
input common mode voltage, V
INCM
, may be indepen-
dently set anywhere within the GND to V
CC
. The DC
common mode input rejection is better than 140dB.
The LTC2412 communicates through a flexible 3-wire
digital interface which is compatible with SPI and
MICROWIRE
TM
protocols.
■
Direct Sensor Digitizer
■
Weight Scales
■
Direct Temperature Measurement
■
Gas Analyzers
■
Strain-Gage Transducers
■
Instrumentation
■
Data Acquisition
■
Industrial Process Control
■
6-Digit DVMs
, LTC and LT are registered trademarks of Linear Technology Corporation.
■
2-Channel Differential Input with Automatic
Channel Selection (Ping-Pong)
■
Low Supply Current: 200µA, 4µA in Autosleep
■
Differential Input and Differential Reference with
GND to V
CC
Common Mode Range
■
2ppm INL, No Missing Codes
■
2.5ppm Full-Scale Error and 0.1ppm Offset
■
0.16ppm Noise, 22.5 Effective Number of Bits
■
No Latency: Digital Filter Settles in a Single Cycle and
Each Channel Conversion is Accurate
■
Internal Oscillator—No External Components
Required
■
110dB Min, 50Hz or 60Hz Notch Filter
■
Narrow SSOP-16 Package
■
Single Supply 2.7V to 5.5V Operation
2-Channel Differential Input
24-Bit No Latency ∆Σ ADC
No Latency ∆Σ is a trademark of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corporation.
V
CC
REF
+
F
O
CH0
+
CH0
–
SCK
REF
–
CH1
+
SDO
GND
CS
114
4
13
3
5
THERMOCOUPLE
6
CH1
–
7
12
8, 9, 10, 15, 16
11
2412 TA01
2
= INTERNAL OSC/50Hz REJECTION
= EXTERNAL CLOCK SOURCE
= INTERNAL OSC/60Hz REJECTION
3-WIRE
SPI INTERFACE
1µF
2.7V TO 5.5V
LTC2412
V
CC
V
IN
(V)
–1.5
TUE (ppm OF V
REF
)
–0.5
0.5
1.5
–1.0
0
1.0
–1.5 –0.5 0.5 1.5
2412 TA02
2.5–2–2.5 –1 0 1 2
T
A
= 90°C
T
A
= –45°C
T
A
= 25°C
V
CC
= 5V
REF
+
= 5V
REF
–
= GND
V
REF
= 5V
V
INCM
= 2.5V
F
O
= GND
Total Unadjusted Error vs Input
APPLICATIO S
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FEATURES
TYPICAL APPLICATIO
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DESCRIPTIO
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