
LTC2356-12/LTC2356-14
1
2356fb
BLOCK DIAGRAM
FEATURES
APPLICATIONS
DESCRIPTION
Serial 12-Bit/14-Bit, 3.5Msps
Sampling ADCs with Shutdown
The LTC2356-12/LTC2356-14 are 12-bit/14-bit, 3.5Msps
serial ADCs with differential inputs. The devices draw
only 5.5mA from a single 3.3V supply and come in a
tiny 10-lead MSOP package. A Sleep shutdown feature
further reduces power consumption to 13W. The com-
bination of speed, low power and tiny package makes the
LTC2356-12/LTC2356-14suitableforhighspeed,portable
applications.
The80dBcommonmoderejectionallowsuserstoeliminate
ground loops and common mode noise by measuring
signals differentially from the source.
The devices convert –1.25V to 1.25V bipolar inputs
differentially. The absolute voltage swing for AIN+ and
AIN– extends from ground to the supply voltage.
Theserialinterfacesendsouttheconversionresultsduring
the 16 clock cycles following a CONV rising edge for com-
patibility with standard serial interfaces. If two additional
clock cycles for acquisition time are allowed after the data
stream in between conversions, the full sampling rate of
3.5Msps can be achieved with a 63MHz clock.
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
SoftSpan is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners.
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3.5Msps Conversion Rate
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74.1dB SINAD at 14-Bits, 71.1dB SINAD at 12-Bits
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Low Power Dissipation: 18mW
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3.3V Single Supply Operation
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2.5V Internal Bandgap Reference can be Overdriven
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3-Wire SPI-Compatible Serial Interface
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Sleep (13W) Shutdown Mode
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Nap (4mW) Shutdown Mode
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80dB Common Mode Rejection
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±1.25V Bipolar Input Range
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Tiny 10-Lead MSOP Package
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Communications
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Data Acquisition Systems
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Uninterrupted Power Supplies
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Multiphase Motor Control
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Multiplexed Data Acquisition
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RFID
THD, 2nd and 3rd vs Input Frequency
for Differential Input Signals
2356 BD
–
+
1
2
7
3
4
S & H
GND
EXPOSED PAD
LTC2356-14
VREF
10F
AIN–
AIN+
14-BIT ADC
3.3V
10F
14
14-BIT
LA
TCH
8
10
9
THREE-
STATE
SERIAL
OUTPUT
PORT
2.5V
REFERENCE
TIMING
LOGIC
VDD
SDO
CONV
SCK
5
6
11
FREQUENCY (MHz)
0.1
–80
THD,
2nd,
3rd
(dB)
–74
–68
–62
–56
1
10
100
2356 G02
–86
–92
–98
–104
–50
THD
2nd
3rd