ADS7865 Datasheet, PDF (1/30 Pages) Texas Instruments – Dual, 12-Bit, 3+3 or 2+2 Channel, Simultaneous Sampling Analog-to-Digital Converter

ADS7865
www.ti.com.............................................................................................................................................................................................. SBAS441 – OCTOBER 2008
Dual, 12-Bit, 3+3 or 2+2 Channel, Simultaneous Sampling
Analog-to-Digital Converter
FEATURES
1
•2 Six Pseudo- or Four Fully Differential Inputs
• SNR: 71.7dB, THD: –87dB
• Programmable Channel Sequencer
• Programmable and Buffered Internal 2.5V
Reference
• Flexible Power-Down Features
• Variable Power-Supply Ranges: 2.7V to 5.5V
• Low-Power Operation: 44mW Maximum at 5V
• Operating Temperature Range:
–40°C to +125°C
• Pin-Compatible Upgrade for the ADS7862
APPLICATIONS
• Motor Control
• Multi-Axis Positioning Systems
• Three-Phase Power Control
DESCRIPTION
The ADS7865 is a dual, 12-bit, 2MSPS
analog-to-digital converter (ADC) with four fully
differential or six pseudo-differential input channels
grouped into two pairs for high-speed, simultaneous
signal acquisition. Inputs to the sample-and-hold
(S/H) amplifiers are fully differential and are
maintained differentially to the input of the ADC. This
architecture provides excellent common-mode
rejection of 72dB at 100kHz, which is a critical
performance characteristic in noisy environments.
The ADS7865 is pin-compatible with the ADS7862,
but offers additional features such as a
programmable channel sequencer and reference
output, flexible supply voltage (2.7V to 5.5V for AV_DD
and BV_DD), a pseudo-differential input multiplexer with
three channels per ADC, and several power-down
features.
The ADS7865 is offered in a TQFP-32 package. It is
specified over the extended operating temperature
range of –40°C to +125°C.
AV_DD
CHA0+
CHA0-
CHA1+
CHA1-
CHB0+
CHB0-
CHB1+
CHB1-
REF_IN
Input
MUX
Input
MUX
REF_OUT
AGND
SAR
S/H
CDAC
Comparator
S/H
CDAC
Comparator
SAR
10-Bit DAC
2.5V Reference
BV_DD
DB[11:0]
CS
CLOCK
WR
RD
BUSY
CONVST
BGND
1
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Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated