LTC2358-18
Buffered Octal, 18-Bit, 200ksps/Ch Differential
±10.24V ADC with 30VP-P Common Mode Range
FEATURES
nn Simultaneous Sampling of 8 Buffered Channels
nn 200ksps per Channel Throughput
nn 500pA/12nA Max Input Leakage at 85°C/125°C
nn ±3.5LSB INL (Maximum, ±10.24V Range)
nn Guaranteed 18-Bit, No Missing Codes
nn Differential, Wide Common Mode Range Inputs
nn Per-Channel SoftSpan Input Ranges:
nn ±10.24V, 0V to 10.24V, ±5.12V, 0V to 5.12V
nn ±12.5V, 0V to 12.5V, ±6.25V, 0V to 6.25V
nn 96.4dB Single-Conversion SNR (Typical)
nn −111dB THD (Typical) at fIN = 2kHz
nn 128dB CMRR (Typical) at fIN = 200Hz
nn Rail-to-Rail Input Overdrive Tolerance
nn Integrated Reference and Buffer (4.096V)
nn SPI CMOS (1.8V to 5V) and LVDS Serial I/O
nn Internal Conversion Clock, No Cycle Latency
nn 219mW Power Dissipation (27mW/Ch Typical)
nn 48-Lead (7mm x 7mm) LQFP Package
APPLICATIONS
nn Programmable Logic Controllers
nn Industrial Process Control
nn Power Line Monitoring
nn Test and Measurement
DESCRIPTION
The LTC®2358-18 is an 18-bit, low noise 8-channel simul-
taneous sampling successive approximation register (SAR)
ADC with buffered differential, wide common mode range
picoamp inputs. Operating from a 5V low voltage supply,
flexible high voltage supplies, and using the internal refer-
ence and buffer, each channel of this SoftSpanTM ADC can be
independently configured on a conversion-by-conversion
basis to accept ±10.24V, 0V to 10.24V, ±5.12V, or 0V to
5.12V signals. Individual channels may also be disabled
to increase throughput on the remaining channels.
The integrated picoamp-input analog buffers, wide input
common mode range and 128dB CMRR of the LTC2358-18
allow the ADC to directly digitize a variety of signals us-
ing minimal board space and power. This input signal
flexibility, combined with ±3.5LSB INL, no missing codes
at 18 bits, and 96.4dB SNR, makes the LTC2358-18 an
ideal choice for many high voltage applications requiring
wide dynamic range.
The LTC2358-18 supports pin-selectable SPI CMOS (1.8V
to 5V) and LVDS serial interfaces. Between one and eight
lanes of data output may be employed in CMOS mode,
allowing the user to optimize bus width and throughput.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
SoftSpan is a trademark of Analog Devices Inc. All other trademarks are the property of their
respective owners. Protected by U.S. Patents, including 7705765, 7961132, 8319673, 9197235.
TYPICAL APPLICATION
15V
5V
0.1µF
0.1µF
2.2µF
1.8V TO 5V
0.1µF
CMOS OR LVDS
I/O INTERFACE
ARBITRARY
+10V
0V
–10V
FULLY
DIFFERENTIAL
+5V
0V
–5V
TRUE BIPOLAR
UNIPOLAR
+10V
+10V
0V
0V
–10V
–10V
DIFFERENTIAL INPUTS IN+/IN– WITH
WIDE INPUT COMMON MODE RANGE
BUFFERS
IN0+
IN0–
S/H
S/H
S/H
S/H
S/H
S/H
S/H
IINN77+–
S/H
EIGHT BUFFERED
SIMULTANEOUS
SAMPLING CHANNELS
VCC
VDD VDDLBYP OVDD LVDS/CMOS
PD
LTC2358-18
SDO0
MUX
18-BIT
SAR ADC
VEE REFBUF REFIN GND
0.1µF
–15V
47µF
0.1µF
SDO7
SCKO
SCKI
SDI
CS
BUSY
CNV
235818 TA01a
SAMPLE
CLOCK
For more information www.linear.com/LTC2358-18
Integral Nonlinearity vs
vsOOuutptpuutt CCooddeeanadnCdhaCnhnaenl nel
2.0
±10.24V RANGE
1.5
TRUE BIPOLAR DRIVE (IN– = 0V)
ALL CHANNELS
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
–131072
–65536
0
65536 131072
OUTPUT CODE
235818 TA01b
235818f
1
