Datasheet

Analog Interface www.ti.com
2 Analog Interface
For maximum flexibility, the AMC7812EVM is designed for easy interfacing to multiple analog sources by
means of different connection options.
2.1 Remote Temperature Inputs Connection
There are two pairs of pins (four pins on the AMC7812: D1+, D1–, D2+ and D2–) that can be connected to
a remote temperature sensor, such as discrete PNP or NPN transistors 2N3906 or 2N3904. On the EVM
board, a 2N3904 is installed on the PCB as an input for D1+ and D1–. A 2N3906 is also installed as the
temperature input for D2+ and D2–. If you would like to use a remote temperature sensor other than that
installed on the board, two analog connectors J6 and J7 (not installed) can be used to route the two
differential analog input signals to pins D1+/D1– and D2+/D2– on the AMC7812.
NOTE: The jumpers JP3/JP4 should be moved to position 1-2 (from the default position 2-3) so that
the onboard 2N3904 can be disconnected if J6 is connected to an external remote sensor.
Additionally, the jumpers at JP5 and JP6 should be moved to position 1-2 so that the
onboard 2N3906 is disconnected if J7 is connected to an external remote sensor.
2.2 ADC Input Connections
The AMC7812 features a 12-bit, successive-approximation register (SAR) ADC, and a 16-channel
multiplexer (mux) that can be programmed to route any one of the 16 channel analog signals to the ADC,
in one of several available input modes: fully differential, pseudo-differential, or single-ended.
Samtec part numbers TSM-118-01-T-DV-P and SSW-110-22-F-D-VS-K provide a convenient 18-pin
header/10-pin socket combination at J1. This header/socket provides access to the ADC related outputs
and related pins of the AMC7812. Consult Samtec at http://www.samtec.com or call 1-800-SAMTEC-9 for
a variety of mating connector options. Table 1 summarizes the pinouts for the ADC input connector J1.
Table 1. J1: ADC Input Connector Pinout
Pin Number Signal Description
J1-2 A
IN
0 Analog input Ch 0
J1-4 A
IN
1 Analog input Ch 1
J1-6 A
IN
2 Analog input Ch 2
J1-8 A
IN
3 Analog input Ch 3
J1-10 A
IN
4 Analog input Ch 4
J1-12 A
IN
5 Analog input Ch 5
J1-14 A
IN
6 Analog input Ch 6
J1-16 A
IN
7 Analog input Ch 7
J1-18 A
IN
8 Analog input Ch 8
J1-20 A
IN
9 Analog input Ch 9
J1-22 A
IN
10 Analog input Ch 10
J1-24 A
IN
11 Analog input Ch 11
J1-26 A
IN
12 Analog input Ch 12
J1-28 A
IN
13 Analog input Ch 13
J1-30 A
IN
14 Analog input Ch 14
J1-32 A
IN
15 Analog input Ch 15
J1-33 AGND Analog ground
J1-35 AGND Analog ground
J1-36 REFIN External reference for ADC
4
AMC7812EVM-PDK User’s Guide SBAU177A–September 2010–Revised May 2013
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated