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Complete 12-Bit ADC in SO-8
Single Supply 5V or ±5V Operation
Sample Rate: 400ksps
Power Dissipation: 75mW (Typ)
72dB S/(N + D) and –80dB THD at Nyquist
No Missing Codes over Temperature
Nap Mode with Instant Wake-Up: 6mW
Sleep Mode: 30μW
High Impedance Analog Input
Input Range (1mV/LSB): 0V to 4.096V or ±2.048V
Internal Reference Can Be Overdriven Externally
3-Wire Interface to DSPs and Processors (SPI and
MICROWIRE
TM
Compatible)
The LTC
®
1400 is a complete 400ksps, 12-bit A/D converter
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
Sleep mode, a reference ready (REFRDY) signal is available
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 efficient data
transfer to a wide range of microprocessors, microcon-
trollers and DSPs.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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
Handheld or Portable Instruments
Single 5V Supply, 400kHz, 12-Bit Sampling A/D Converter
5V
SUPPLY CURRENT (mA)
+
ANALOG INPUT
(0V TO 4.096V)
2.42V REF
OUT
10µF
V
CC
10µF
0.1µF
LTC1400
A
IN
V
REF
0.1µF
GND
+
U
TYPICAL APPLICATIO
Power Consumption vs Sample Rate
100
NORMAL CONVERSION
NAP MODE
BETWEEN CONVERSION
SLEEP AND NAP MODE
BETWEEN CONVERSION
SLEEP MODE BETWEEN
CONVERSION
6.4MHz CLOCK
10
V
SS
MPU
P1.4
P1.3
SERIAL
DATA LINK
P1.2
1
CONV
CLK
D
OUT
0.1
0.01
1400 TA01
0.001
0.01 0.1
U
FEATURES
LTC1400
Complete SO-8, 12-Bit,
400ksps ADC with
Shutdown
DESCRIPTIO
U
1
10 100 1k 10k 100k 1M
SAMPLE RATE (Hz)
1400 TA02
1400fa
1
LINER [ LINEAR TECHNOLOGY ]
