LTC2348-18_15 Datasheet, PDF (1/42 Pages) Linear Technology – Octal, 18-Bit, 200ksps Differential 10.24V Input SoftSpan ADC with Wide Input Common Mode Range

LTC2348-18
Features
Octal, 18-Bit, 200ksps
Differential ±10.24V Input SoftSpan ADC
with Wide Input Common Mode Range
Description
nn _{200ksps per Channel Throughput}
nn _{Eight Simultaneous Sampling Channels}
nn _{±3LSB 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:}
±10.24V, 0V to 10.24V, ±5.12V, 0V to 5.12V
nn _{96.7dB Single-Conversion SNR (Typical)}
nn _{−109dB THD (Typical) at fIN = 2kHz}
nn _{118dB CMRR (Typical) at fIN = 200Hz}
nn _{Rail-to-Rail Input Overdrive Tolerance}
nn _{Guaranteed Operation to 125°C}
nn _{Integrated Reference and Buffer (4.096V)}
nn _{2.5V to 5V External Reference Input Range}
nn _{SPI CMOS (1.8V to 5V) and LVDS Serial I/O}
nn _{Internal Conversion Clock, No Cycle Latency}
nn _{140mW Power Dissipation (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}
The LTC^®2348-18 is an 18-bit, low noise 8-channel si-
multaneous sampling successive approximation register
(SAR) ADC with differential, wide common mode range
inputs. Operating from a 5V low voltage supply, flexible
high voltage supplies, and using the internal reference
and buffer, each channel of this SoftSpan^TM 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 wide input common mode range and 118dB CMRR of
the LTC2348-18 analog inputs allow the ADC to directly
digitize a variety of signals, simplifying signal chain de-
sign. This input signal flexibility, combined with ±3LSB
INL, no missing codes at 18 bits, and 96.7dB SNR, makes
the LTC2348-18 an ideal choice for many high voltage
applications requiring wide dynamic range.
The LTC2348-18 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 Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents, including 7705765, 7961132, 8319673.
Other Patents pending.
Typical Application
15V
5V
0.1µF 0.1µF
2.2µF
1.8V TO 5V
0.1µF
ARBITRARY
+10V
0V
–10V
FULLY
DIFFERENTIAL
+10V
0V
–10V
TRUE BIPOLAR
UNIPOLAR
+10V
+10V
0V
0V
–10V
–10V
DIFFERENTIAL INPUTS IN+/IN– WITH
WIDE INPUT COMMON MODE RANGE
IN0+
IN0–
S/H
S/H
S/H
S/H
S/H
S/H
S/H
IINN77+– _S/H
EIGHT SIMULTANEOUS
SAMPLING CHANNELS
CMOS OR LVDS
I/O INTERFACE
V_CC
V_DD V_DDLBYP OV_{DD LVDS/CMOS}
PD
LTC2348-18
SDO0
MUX
18-BIT
SAR ADC
V_EE REFBUF REFIN GND
0.1µF
–15V
47µF
0.1µF
SDO7
SCKO
SCKI
SDI
CS
BUSY
CNV
234818 TA01a
SAMPLE
CLOCK
For more information www.linear.com/LTC2348-18
Integral Nonlinearity vs
v^IOns^tueO^gtu^prt^ap^ulu^tNt^CoC^noo^ld^dine^{eeaarnityd Channel}
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
234818 G01
234818f
1