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LTC1402
Serial 12-Bit, 2.2Msps
Sampling ADC with Shutdown
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Sample Rate: 2.2Msps
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72dB S/(N + D) and –89dB THD at Nyquist
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Power Dissipation: 90mW (Typ)
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80MHz Full Power Bandwidth Sampling
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No Missing Codes over Temperature
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Available in 16-Pin Narrow SSOP Package
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Single Supply 5V or
±5V Operation
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Nap Mode with Instant Wake-Up: 15mW
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Sleep Mode: 10
W
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True Differential Inputs Reject Common Mode Noise
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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
MICROWIRE
TM Compatible)
The LTC
1402 is a 12-bit, 2.2Msps sampling A/D con-
verter. This high performance device includes a high dy-
namic range sample-and-hold and a precision reference.
It operates from a single 5V supply or dual
±5V supplies
and draws only 90mW from 5V.
The versatile differential input offers a unipolar range of
4.096V and a bipolar range of
±2.048V for dual supply
systems where high performance op amps perform best,
eliminating the need for special translation circuitry.
The high common mode rejection allows users to elimi-
nate ground loops and common mode noise by measuring
signals differentially from the source.
Outstanding AC performance includes 72dB S/(N + D) and
–93dB SFDR at the Nyquist input frequency of 1.1MHz
with dual
±5V supplies and –84dB SFDR with a single 5V
supply.
The LTC1402 has two power saving modes: Nap and
Sleep. Nap mode consumes only 15mW of power and can
wake up and convert immediately. In Sleep mode, it
typically consumes 10
W of power. Upon power-up from
Sleep mode, a reference ready (REFRDY) signal is avail-
able in the serial data word to indicate that the reference
has settled and the chip is ready to convert.
The 3-wire serial port allows compact and efficient data
transfer to a wide range of microprocessors, microcon-
trollers and DSPs. A digital output driver power supply pin
allows direct connection to 3V or lower logic.
SAMPLE-
AND-HOLD
DOUT
BIP/UNI
CONV
SCK
OVDD
10
8
16
15
DVDD
AVDD
112
11
GAIN
7
5
4
3
–5V OR 0V
10
F
10
F
VREF
4.096V
10
F
64k
OUTPUT
BUFFER
1402 TA01
2.048
REFERENCE
TIMING
LOGIC
AIN
+
LTC1402
OGND
9
6
2
DGND
AIN
–
5V
3V OR 5V
AGND1
14
13
AGND2
+
–
64k
12-BIT ADC
VSS
MICROWIRE is a trademark of National Semiconductor Corp.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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Telecommunications
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High Speed Data and Signal Acquisition
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Digitally Multiplexed Data Acquisition Systems
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Digital Radio Receivers
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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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Imaging Systems
5 Harmonic THD, 2nd, 3rd and SFDR
vs Input Frequency (Unipolar)
INPUT FREQUENCY (Hz)
104
105
106
107
–80
THD,
SFDR,
2ND
3RD
(dB)
–60
–40
1401 G05
–100
–120
0
–20
–90
–70
–50
–110
–10
–30
THD
SFDR
2ND
3RD
fSAMPLE = 2.22MHz
APPLICATIO S
U
DESCRIPTIO
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FEATURES
BLOCK DIAGRA
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