LTC2442
1
2442fb
For more information www.linear.com/LTC2442
V
IN
DIFFERENTIAL (V)
–2.048
–5
INL ERROR (ppm)
–4
–2
–1
0
5
2
–1.024
0
2442 TA02
–3
3
4
1
1.024
2.048
V
INCM
= 2.048V
V
REF
= 4.096V
V
CC
= 5V
V
+
= 5V
V
–
= 0V
24-Bit High Speed
4-Channel DS ADC
with Integrated Amplifier
The LTC
®
2442 is an ultra high precision, variable speed,
24-bit DS
™
ADC with integrated amplifier. The amplifier
can be configured as a buffer for easy input drive of high
impedance sensors. 1 part-per-million (ppm) linearity is
achievable when the amplifier is configured in unity gain.
External resistors can be used to set a gain for increased
resolution of low level input signals. The positive and
negative amplifier supply pins may be tied directly to V
CC
(4.5V to 5.5V) and GND or biased above V
CC
and below
GND for rail-to-rail input signals.
The proprietary DS architecture ensures stable DC ac
-
curacy through continuous transparent calibration. Ten
speed/resolution combinations from 6.9Hz/220nV
RMS
to
3.5kHz/25µV
RMS
can be selected with no latency or shift
in DC accuracy. Additionally, a 2X speed mode can be
selected enabling output rates up to 7kHz (8kHz with an
external oscillator) with one cycle latency.
Any combination of single-ended (up to 4 inputs) or dif
-
ferential (up to
2
inputs) can be selected with a common
mode input range from ground to V
CC
. While operating in
the 1X speed mode the first conversion following a new
speed/resolution or channel selection is valid.
n
Auto Ranging 6-Digit DVMs
n
High Speed Multiplexing
n
Weight Scales
n
Direct Temperature Measurement
n
High Speed Data Acquisition
n
1ppm Linearity with No Missing Codes
n
Integrated Amplifier for Direct Sensor Digitization
n
2 Differential or 4 Single-Ended Input Channels
n
Up to 8kHz Output Rate (External f
O
)
n
Up to 4kHz Multiplexing Rate (External f
O
)
n
Selectable Speed/Resolution
2.1µV
RMS
Noise at 1.76kHz Output Rate
220nV
RMS
Noise at 13.8Hz Output Rate with
Simultaneous 50Hz/60Hz Rejection
n
Guaranteed Modulator Stability and Lock-Up
Immunity for any Input and Reference Conditions
n
<5µV Offset (4.5V < V
CC
< 5.5V, –40°C to 85°C)
n
Differential Input and Differential Reference with GND
to V
CC
Common Mode Range
n
No Latency Mode, Each Conversion is Accurate Even
After a New Channel is Selected
n
Internal Oscillator—No External Components
n
36-Lead SSOP Package
High Precision Data Acquisition System
LTC2442 Integral Non-Linearity
SDI
SCK
SDO
CS
F
O
V
CC
4.5V TO 5.5V4.5V TO 15V
–15V TO 0V
0.1µF
GND
V
REF
–
V
REF
+
2442 TA01
4-WIRE
SPI INTERFACE
LTC2442
= EXTERNAL OSCILLATOR
= INTERNAL OSCILLATOR
(SIMULTANEOUS 50Hz/60Hz
REJECTION AT 6.9Hz OUTPUT RATE)
CH0
CH1
CH2
CH3
COM
0.1µF
AUTO-CAL
VARIABLE SPEED/
RESOLUTION
DIFFERENTIAL
24-BIT ∆Σ ADC
HIGH Z
2-CHANNEL
DIFFERENTIAL/
4-CHANNEL
SINGLE ENDED
–
+
–
+
V
+
V
–
FEATURES
APPLICATIONS
DESCRIPTION
TYPICAL APPLICATION
L, LT, LT C , LT M, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. No Latency DS and SoftSpan are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners. Protected by U.S.
Patents including 6140950, 6169506, 6411242, 6639526.
