
LTC1400
1
1400fa
Complete SO-8, 12-Bit,
400ksps ADC with
Shutdown
TheLTC1400isacomplete400ksps,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 exibility 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.
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
DNL and 45ppm/°C drift over temperature. Guaranteed AC
performance includes 70dB S/(N + D) and –76dB THD at
an input frequency of 100kHz, over temperature.
The 3-wire serial port allows compact and efcient data
transfer to a wide range of microprocessors, microcon-
trollers and DSPs.
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High Speed Data Acquisition
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Digital Signal Processing
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Multiplexed Data Acquisition Systems
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Audio and Telecom Processing
■
Digital Radio
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Spectrum Analysis
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Low Power and Battery-Operated Systems
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Handheld or Portable Instruments
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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
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Power Dissipation: 75mW (Typ)
■
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
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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)
Single 5V Supply, 400kHz, 12-Bit Sampling A/D Converter
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
VCC
AIN
VREF
GND
VSS
CONV
CLK
DOUT
MPU
P1.4
P1.3
P1.2
LTC1400
+
0.1
F
10
F
+
0.1
F
10
F
2.42V REFOUT
ANALOG INPUT
(0V TO 4.096V)
SERIAL
DATA LINK
5V
1400 TA01
SAMPLE RATE (Hz)
0.01
SUPPLY
CURRENT
(mA)
100
10
1
0.1
0.01
0.001
10
1k
1M
1400 TA02
0.1
1
100
10k 100k
NORMAL CONVERSION
NAP MODE
BETWEEN CONVERSION
SLEEP AND NAP MODE
BETWEEN CONVERSION
SLEEP MODE BETWEEN
CONVERSION
6.4MHz CLOCK
Power Consumption vs Sample Rate