LTC1400
Complete SO-8, 12-Bit,
400ksps ADC with
Shutdown
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DESCRIPTIO
FEATURES
TheLTC®1400isacomplete400ksps,12-bitA/Dconverter
which draws only 75mW from 5V or ±5V supplies. This
easy-to-use device comes complete with a 200ns sample-
and-hold and a precision reference. Unipolar and bipolar
conversion modes add to the flexibility of the ADC. The
LTC1400 has two power saving modes: Nap and Sleep.
In Nap mode, it consumes only 6mW of power and can
wake up and convert immediately. In the Sleep mode, it
consumes 30μW of power typically. Upon power-up from
Sleepmode,areferenceready(REFRDY)signalisavailable
in the serial data word to indicate that the reference has
settled and the chip is ready to convert.
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Complete 12-Bit ADC in SO-8
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Single Supply 5V or ±5V Operation
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Sample Rate: 400ksps
Power Dissipation: 75mW (Typ)
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72dB S/(N + D) and –80dB THD at Nyquist
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No Missing Codes over Temperature
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Nap Mode with Instant Wake-Up: 6mW
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Sleep Mode: 30μW
High Impedance Analog Input
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Input Range (1mV/LSB): 0V to 4.096V or ±2.048V
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Internal Reference Can Be Overdriven Externally
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3-Wire Interface to DSPs and Processors (SPI and
MICROWIRETM Compatible)
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The LTC1400 converts 0V to 4.096V unipolar inputs from
a single 5V supply and ±2.048V bipolar inputs from ±5V
supplies. Maximum DC specs include ±1LSB INL, ±1LSB
DNLand45ppm/°Cdriftovertemperature.GuaranteedAC
performance includes 70dB S/(N + D) and –76dB THD at
an input frequency of 100kHz, over temperature.
APPLICATIO S
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High Speed Data Acquisition
Digital Signal Processing
Multiplexed Data Acquisition Systems
Audio and Telecom Processing
Digital Radio
Spectrum Analysis
Low Power and Battery-Operated Systems
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The 3-wire serial port allows compact and efficient data
transfer to a wide range of microprocessors, microcon-
trollers and DSPs.
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, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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Handheld or Portable Instruments
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TYPICAL APPLICATIO
Single 5V Supply, 400kHz, 12-Bit Sampling A/D Converter
Power Consumption vs Sample Rate
100
NORMAL CONVERSION
10
5V
NAP MODE
BETWEEN CONVERSION
1
V
V
SS
CC
+
10µF
0.1µF
MPU
P1.4
LTC1400
SLEEP AND NAP MODE
ANALOG INPUT
(0V TO 4.096V)
A
V
CONV
CLK
IN
0.1
0.01
BETWEEN CONVERSION
SLEEP MODE BETWEEN
CONVERSION
2.42V REF
P1.3
P1.2
REF
OUT
+
GND
D
10µF
0.1µF
OUT
SERIAL
DATA LINK
6.4MHz CLOCK
0.001
1400 TA01
100
SAMPLE RATE (Hz)
0.01 0.1
1
10
1k 10k 100k 1M
1400 TA02
1400fa
1