Техническая Спецификация для Texas Instruments DDC11XEVM-PDK - DDC11xEVM-PDK Evaluation Module DDC11XEVM-PDK DDC11XEVM-PDK
Модели
DDC11XEVM-PDK
Z
3
Z
4
P
3
P
4
P
1
P
2
P
6
P
5
P
7
Z
2
P
11
P
12
Z
6
Z
1
P
9
P
10
J4
J3
J2
P
8
Z
5
IN1 (Pin 1)
DDC112U
(DUT)
IN2 (Pin 28)
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DDC112EVM Hardware Description
Table 2. Jumper Setting Definitions for JP1 for the Voltage Reference Source for
the DDC112
Jumper Setting
Jumper Setting Function
Position A
Connects the 4.096V onboard reference to the DUT.
Position B
Connects the EXT VREF connector, J5, to the DUT.
Position C
Connects the breadboard VREF bus to the DUT.
3.2
Optional Component Sockets
Resistor and capacitor socket locations are included on the DDC112EVM DUT board to allow for optional
input circuits and easy insertion of the optional external gain capacitors.
input circuits and easy insertion of the optional external gain capacitors.
Figure 5. Input Structure on the DDC112EVM DUT Board
shows the topology of the input socket options and BNC connectors. For this input structure to
work as shown, jumpers JP2 and JP3 must be removed from the DDC112 DUT board so that R6 and R7
have no effect at the input. To simplify the diagram JP2, JP3, R6, and R7 are not shown. Using this
arrangement, several different input configurations can be implemented on the DDC112 DUT board. For
example, a photosensor can be installed for the IN1 (pin 1 of the DUT) using the P
have no effect at the input. To simplify the diagram JP2, JP3, R6, and R7 are not shown. Using this
arrangement, several different input configurations can be implemented on the DDC112 DUT board. For
example, a photosensor can be installed for the IN1 (pin 1 of the DUT) using the P
3
and P
4
sockets.
Alternatively, a voltage source could be used to excite the input of the converter by using J2 with a resistor
installed in the Z
installed in the Z
1
position (P
1
and P
2
) sockets. Both of these configurations can be implemented on the
IN2 (pin 28) input as well. A dc offset current can be injected into the input through J3. A resistor in the Z
3
position should be inserted if the source from J3 is voltage. A short should be inserted if the source is a
current. It can be quickly seen that a variety of configurations can be implemented with this input circuitry
configuration. The factory setting for this circuit is all input sockets open. The default inputs to the DDC112
connect to R6 and R7, which are 10M
current. It can be quickly seen that a variety of configurations can be implemented with this input circuitry
configuration. The factory setting for this circuit is all input sockets open. The default inputs to the DDC112
connect to R6 and R7, which are 10M
Ω
resistors. The input to the resistors can be selected using the
jumpers JP2 and JP3. JP2 is used as an input selection for IN1 of the DDC112, and can be selected to
receive an input from J2 or J3. JP3 is used to select the input for IN2 of the DDC112 and can receive an
input from J3 or J4. The factory default setting for JP2 and JP3 is J3 (INPUT CM).
receive an input from J2 or J3. JP3 is used to select the input for IN2 of the DDC112 and can receive an
input from J3 or J4. The factory default setting for JP2 and JP3 is J3 (INPUT CM).
7
SLAU234A – October 2007 – Revised July 2010
DDC11xEVM-PDK User's Guide
Copyright © 2007–2010, Texas Instruments Incorporated