Analog Interface; P2: Analog Interface Pinout (Samtec 10 X 2); Sma Analog Inputs - Texas Instruments ADS794x EVM Series User Manual

Analog Interface

2 Analog Interface
The ADS794xEVM is designed for easy interfacing to multiple analog sources. SMA connectors allow the
EVM to have input signals connected via coaxial cables. In addition, the Samtec connector provides a
convenient 10-pin, dual-row, header/socket combination at P2. This header/socket provides access to the
analog input pins of the ADS794x. Consult Samtec at
a variety of mating connector options. All analog inputs are buffered by OPA836 high-speed operational
amplifiers in order to properly drive the ADS794x ADC inputs.
Use appropriate caution when handling these pins.
Pin Number
P2.2
P2.4
P2.10
P2.12
P2.1-19 (odd)
P2.6 and P2.8
P2.14, P2.16, and P2.18
P2.15
P2.20
Table 2 lists the SMA analog inputs.
Pin Number
J10
J11
J4
J5
As noted in Table 1
converter. The ADS7945 uses two inputs per channel because of its fully differential inputs. The ADS7946
uses one input per channel for its pseudo-differential inputs.
4
ADS794xEVM and ADS794xEVM-PDK
Table 1. P2: Analog Interface Pinout (Samtec 10 x 2)
Signal
A0(+) / OPEN
A0(–)
A1(+) / OPEN
A1(–)
GND
GND
GND
V /4 or V /2
REF REF
Ext V
REF
Table 2. SMA Analog Inputs
Signal
A0(+) / No SMA
A0(–)
A1(+) / No SMA
A1(–)
and Table 2, there are different hardware configurations depending on the installed
Copyright © 2011, Texas Instruments Incorporated
http://www.samtec.com
Table 1 summarizes the pinout for analog interface P2.
Description
CH0 positive differential input for ADS7945; open if
ADS7946 is installed
CH0 negative differential input for ADS7945;
single-ended input for ADS7946
CH1 positive differential input for ADS7945; open if
ADS7946 is installed
CH1 negative differential input for ADS7945;
single-ended input for ADS7946
Analog ground connections (except J1.15)
Analog ground connections
Analog ground connections
Unbuffered output. V /4 (J6 open) or V
REF
closed)
External reference voltage input
Description
CH0 positive differential input for ADS7945; no
SMA if ADS7946 is installed
CH0 negative differential input for ADS7945;
single-ended input for ADS7946
CH1 positive differential input for ADS7945; no
SMA if ADS7946 is installed
CH1 negative differential input for ADS7945;
single-ended input for ADS7946
www.ti.com
or call 1-800-SAMTEC-9 for
/2 (J6
REF
SBAU194 – August 2011
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