LTC2356-12/LTC2356-14
Serial 12-Bit/14-Bit, 3.5Msps
Sampling ADCs with Shutdown
Description
Features
n
n
n
n
n
n
n
n
n
n
n
3.5Msps Conversion Rate
74.1dB SINAD at 14-Bits, 71.1dB SINAD at 12-Bits
Low Power Dissipation: 18mW
3.3V Single Supply Operation
2.5V Internal Bandgap Reference can be Overdriven
3-Wire SPI-Compatible Serial Interface
Sleep (13µW) Shutdown Mode
Nap (4mW) Shutdown Mode
80dB Common Mode Rejection
±1.25V Bipolar Input Range
Tiny 10-Lead MSOP Package
The LTC®2356-12/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 13µW. The combination of speed, low power and tiny package makes the
LTC2356-12/LTC2356-14 suitable for high speed, portable
applications.
The 80dB common mode rejection allows users to eliminate
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.
Applications
Communications
Data Acquisition Systems
n Uninterrupted Power Supplies
n Multiphase Motor Control
n Multiplexed Data Acquisition
n RFID
n
n
The serial interface sends out the conversion results during
the 16 clock cycles following a CONV rising edge for compatibility 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.
Block Diagram
THD, 2nd and 3rd vs Input Frequency
for Differential Input Signals
10µF 3.3V
1
+
14-BIT ADC
S&H
AIN–
2
–
–56
THREESTATE
SERIAL
OUTPUT
PORT
–62
SDO
8
14
3
VREF
10
2.5V
REFERENCE
10µF
4
GND
5
11
EXPOSED PAD
–68
–74
THD
2nd
3rd
–80
–86
–92
SCK
9
6
CONV
TIMING
LOGIC
THD, 2nd, 3rd (dB)
AIN+
–50
VDD
14-BIT LATCH
7
LTC2356-14
2356 BD
–98
–104
0.1
1
10
FREQUENCY (MHz)
100
2356 G02
2356fd
For more information www.linear.com/LTC2356-12
1
