LTC2373-18
18-Bit, 1Msps, 8-Channel
SAR ADC with 100dB SNR
FeaTures
DescripTion
The LTC®2373-18 is a low noise, high speed, 8-channel
18-bitsuccessiveapproximationregister(SAR)ADC.Oper-
atingfromasingle5Vsupply,theLTC2373-18hasahighly
configurable, low crosstalk 8-channel input multiplexer,
supporting fully differential, pseudo-differential unipolar
and pseudo-differential bipolar analog input ranges. The
LTC2373-18 achieves 2.75LSB INL (maximum) in all
inputranges, nomissingcodesat18-bitsand100dB(fully
differential)/ 95dB (pseudo-differential) SNR (typical).
n
1Msps Throughput Rate
n
18-Bit Resolution with No Missing Codes
n
8-Channel Multiplexer with Selectable Input Range
n
Fully Differential (±±4.096V
n
Pseudo-Differential Unipolar (.6 to ±4.096V
n
Pseudo-Differential Bipolar (±ꢀ4.±86V
n
INL: ±ꢀ4ꢁ7LSB (MaxiꢂuꢂV
n
SNR: 1..dB (Fully DifferentialV/07dB (Pseudo-
DifferentialV (TypicalV at f = 1kHz
IN
IN
n
n
n
n
n
n
n
n
n
n
THD: –11.dB (TypicalV at f = 1kHz
TheLTC2373-18hasanonboardlowdrift(20ppm/°Cmax)
2.048V temperature-compensated referenceanda single-
shot capable reference buffer. The LTC2373-18 also has a
high speed SPI-compatible serial interface that supports
1.8V, 2.5V, 3.3V and 5V logic through which a sequencer
with a depth of 16 may be programmed. An internal os-
cillator sets the conversion time, easing external timing
considerations. The LTC2373-18 dissipates only 40mW
and automatically naps between conversions, leading to
reduced power dissipation that scales with the sampling
rate. A sleep mode is also provided to reduce the power
consumption of the LTC2373-18 to 300μW for further
power savings during inactive periods.
Programmable Sequencer
Selectable Digital Gain Compression
Single 5V Supply with 1.8V to 5V I/O Voltages
SPI-Compatible Serial I/O
Onboard 2.048V Reference and Reference Buffer
No Pipeline Delay, No Cycle Latency
Power Dissipation 40mW (Typical)
Guaranteed Operation to 125°C
32-Lead 5mm × 5mm QFN Package
applicaTions
n
Programmable Logic Controllers
n
Industrial Process Control
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. Protected by U.S. Patents, including 7705765, 7961132, 8319673.
n
High Speed Data Acquisition
n
Portable or Compact Instrumentation
n
ATE
Integral Nonlinearity
Typical applicaTion
vs Output Code
5V
2.0
4.096V
1.8V TO 5V
FULLY DIFFERENTIAL
BIPOLAR
UNIPOLAR
0V
1.5
1.0
10µF
2.2µF
0.1µF
0V
10Ω
V
V
OV
DD
DD
DDLBYP
0.5
4.096V
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
RESET
RDL
+
LTC2373-18
1200pF
1200pF
0V
4.096V
0V
0
+
–
MUX
18-BIT
SAMPLING ADC
SDO
SCK
SDI
BUSY
CNV
10Ω
–0.5
–1.0
–1.5
–2.0
–
SAMPLE
CLOCK
4.096V
0V
REFBUF REFIN
47µF 0.1µF
GND
237318 TA01a
0
65536
131072
OUTPUT CODE
196608
262144
2.048V
2373 TA01b
237318f
1
For more information www.linear.com/LTC2373-18