鈭單?/div>
TM
ADCs
FEATURES
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DESCRIPTIO
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Pin Compatible 4-/8-Channel 24-Bit ADCs
Single Conversion Digital Filter Settling Time
Simplifies Multiplexing
4ppm INL, No Missing Codes
4ppm Full-Scale Error
0.5ppm Offset
0.3ppm Noise
Internal Oscillator鈥擭o External Components
Required
110dB Min, 50Hz/60Hz Notch Filter
Reference Input Voltage: 0.1V to V
CC
Live Zero鈥擡xtended Input Range Accommodates
12.5% Overrange and Underrange
Single Supply 2.7V to 5.5V Operation
Low Supply Current (200碌A(chǔ)) and Auto Shutdown
The LTC
廬
2404/LTC2408 are 4-/8-channel 2.7V to 5.5V
micropower 24-bit A/D converters with an integrated
oscillator, 4ppm INL and 0.3ppm RMS noise. They use
delta-sigma technology and provide single cycle digital
filter settling time (no latency delay) for multiplexed
applications. The first conversion after the channel is
changed is always valid. Through a single pin the LTC2404/
LTC2408 can be configured for better than 110dB rejec-
tion at 50Hz or 60Hz
鹵2%,
or can be driven by an external
oscillator for a user defined rejection frequency in the
range 1Hz to 120Hz. The internal oscillator requires no
external frequency setting components.
The converters accept any external reference voltage from
0.1V to V
CC
. With their extended input conversion range of
鈥?2.5% V
REF
to 112.5% V
REF
the LTC2404/LTC2408
smoothly resolve the offset and overrange problems of
preceding sensors or signal conditioning circuits.
The LTC2404/LTC2408 communicate through a flexible
4-wire digital interface which is compatible with SPI and
MICROWIRE
TM
protocols.
, LTC and LT are registered trademarks of Linear Technology Corporation.
No Latency
鈭單?/div>
is a trademark of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corporation.
APPLICATIO S
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Weight Scales
Direct Temperature Measurement
Gas Analyzers
Strain-Gage Transducers
Instrumentation
Data Acquisition
Industrial Process Control
6-Digit DVMs
TYPICAL APPLICATIO
7
MUXOUT
9 CH0
10 CH1
11 CH2
ANALOG
INPUTS
鈥?.12V
REF
TO
1.12V
REF
12 CH3
13 CH4*
14 CH5*
15 CH6*
17 CH7*
6 COM
4-/8-CHANNEL
MUX
0.1V TO V
CC
4
ADCIN
3
2, 8
V
REF
V
CC
CSADC
CSMUX
24-BIT
鈭嗏垜
ADC
SCK
CLK
D
IN
SDO
2.7V TO 5.5V
10
1碌F
8
V
DD
= 5V
V
REF
= 5V
T
A
= 25擄C
F
O
= LOW
LINEARITY ERROR (ppm)
23
20
19
25
21
24
SERIAL DATA LINK
MICROWIRE AND
SPI COMPATABLE
+
MPU
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LTC2404/LTC2408
GND
1, 5, 16, 18, 22, 27, 28
V
CC
F
O
2404/08 TA01
26
= INTERNAL OSC/50Hz REJECTION
= EXTERNAL CLOCK SOURCE
= INTERNAL OSC/60Hz REJECTION
*THESE PINS ARE NO CONNECTS ON THE LTC2404
U
Total Unadjusted Error vs Output Code
6
4
2
0
鈥?
鈥?
鈥?
鈥?
鈥?0
0
8,338,608
OUTPUT CODE (DECIMAL)
16,777,215
2404/08 TA02
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