Document
LTC2345-16
Features
Octal, 16-Bit, 200ksps Differential SoftSpan ADC with Wide Input Common Mode Range
Description
nn 200ksps per Channel Throughput nn Eight Simultaneous Sampling Channels nn ±1.25LSB INL (Maximum) nn Guaranteed 16-Bit, No Missing Codes nn Differential, Wide Common Mode Range Inputs nn Per-Channel SoftSpan Input Ranges:
±4.096V, 0V to 4.096V, ±2.048V, 0V to 2.048V ±5V, 0V to 5V, ±2.5V, 0V to 2.5V nn 91dB Single-Conversion SNR (Typical) nn −113dB THD (Typical) at fIN = 2kHz nn 102dB 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 SPI CMOS (1.8V to 5V) and LVDS Serial I/O nn Internal Conversion Clock, No Cycle Latency nn 81mW Power Dissipation (Typical) nn 48-Lead (7mm x 7mm) QFN Package
Applications
nn Programmable Logic Controllers nn Industrial Process Control nn Medical Imaging nn High Speed Data Acquisition
The LTC®2345-16 is a 16-bit, low noise 8-channel simultaneous sampling successive approximation register (SAR) ADC with differential, wide common mode range inputs. Operating from a 5V low voltage supply and using the internal reference and buffer, each channel of this SoftSpanTM ADC can be independently configured on a conversion-by-conversion basis to accept ±4.096, 0V to 4.096V, ±2.048V, or 0V to 2.048V signals. Individual channels may also be disabled to increase throughput on the remaining channels.
The wide input common mode range and 102dB CMRR of the LTC2345-16 analog inputs allow the ADC to directly digitize a variety of signals, simplifying signal chain design. This input signal flexibility, combined with ±1.25LSB INL, no missing codes at 16 bits, and 91dB SNR, makes the LTC2345-16 an ideal choice for many applications requiring wide dynamic range.
The LTC2345-16 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
ARBITRARY 5V
FULLY DIFFERENTIAL 5V
0V
BIPOLAR 5V
0V
UNIPOLAR 5V
0V
0V
DIFFERENTIAL INPUTS IN+/IN– WITH WIDE INPUT COMMON MODE RANGE
IINN00+– S/H S/H S/H S/H S/H S/H S/H
IINN77+– S/H
EIGHT SIMULTANEOUS SAMPLING CHANNELS
••• •••
5V
0.1µF
2.2µF
1.8V TO 5V 0.1µF
CMOS OR LVDS I/O INTERFACE
VDD VDDLBYP OVDD LVDS/CMOS PD
LTC2345-16
SDO0
MUX
16-BIT SAR ADC
REFBUF REFIN GND
47µF
0.1µF
SDO7 SCKO SCKI
SDI CS BUSY CNV
234516 TA01a
SAMPLE CLOCK
For more information www.linear.com/LTC2345-16
INL ERROR (LSB)
Integral Nonlinearity vs Output Code and Channel
1.00
±4.096V RANGE
0.75
FULLY DIFFERENTIAL DRIVE (IN– = –IN+)
ALL CHAN.