Datasheet

EVAL-AD7400/AD7401
Rev. 0 | Page 4 of 12
Link No. Function
J14 This link option selects the source of the V
IN
− analog input to the AD7400 or AD7401.
In Position A, the V
IN
− analog input to the AD7400 or AD7401 is buffered by the AD797 (U3). This link option should
be used in conjunction with J13, which should be placed in Position A.
In Position B, the V
IN
− analog input to the AD7400 or AD7401 is not buffered by the AD797 (U3). This link option
should be used in conjunction with J13, which should be placed in Position B.
In Position C, the V
IN
− analog input to the AD7400 or AD7401 is tied directly to GND
1
.
MCLKOUT/MCLKIN
This is a solder link that selects the destination of the MCLKOUT for the AD7400 and the source of the MCLKIN for
the AD7401.
In Position A, the MCLKOUT/MCLKIN pin of the AD7400 or AD7401 is tied directly to GND
2
.
In Position B, the MCLKOUT/MCLKIN pin of the AD7400 or AD7401 is connected directly to J7, that is, the signal is
received/supplied by either the EVAL-CED1Z or an external source via the J5 SMB socket.
MDAT This is a solder link that selects the destination of the MDAT for the AD7400 or AD7401.
In Position A, the MDAT pin of the AD7400 or AD7401 is tied directly to GND
2
.
In Position B, the MDAT pin of the AD7400 or AD7401 is connected directly to J8, that is, the signal is received by
either the EVAL-CED1Z or an external source via the J6 SMB socket.
Table 2.Link Positions on the Packaged EVAL-AD7400/AD7401
Link No. Position Function
J7 A
The MCLKOUT signal from the AD7400 is supplied to the EVAL-CED1Z. The MCLKIN signal from the
AD7401 is supplied by the EVAL-CED1Z.
J8 A The MDAT signal from the AD7400 or AD7401 is supplied directly to the EVAL-CED1Z.
J9 A
The V
DD2
supply (the nonisolated supply) for the AD7400 or AD7401 is supplied by a 3.3 V supply from an
external source via the J4 connector.
J10 B
The V
IN
+ analog input to the AD7400 or AD7401 is not buffered by the AD797 (U2). This link option should
be used in conjunction with J11, which should be placed in Position B.
J11 B
The analog input signal supplied to the J2 SMB is fed directly to the V
IN
+ input of the AD7400 or AD7401;
therefore, it is not buffered. This link option should be used in conjunction with J10, which should be
placed in Position B.
J13 B
The analog input signal supplied to the J3 SMB is fed directly to the V
IN
− input of the AD7400 or AD7401;
therefore, it is not buffered.
J14 C The V
IN
− analog input to the AD7400 or AD7401 is tied directly to GND
1
.
MCLKOUT/MCLKIN B The MCLKOUT/MCLKIN pin of the AD7400 or AD7401 is connected directly to J7.
MDAT B The MDAT pin of the AD7400 or AD7401 is connected directly to J8.
SETUP CONDITIONS
Care should be taken before applying power and signals to
the evaluation board. It is necessary to ensure that all links are
positioned correctly for the chosen operating mode. There are
two different modes in which to operate the evaluation board.
The user can either operate the board with the EVAL-CED1Z
or it can be used as a standalone board.
Table 2 shows the position in which all the links are set when
the evaluation board is packaged. When the board is shipped,
it is assumed that the user operate with the EVAL-CED1Z
board. The links are set so that the control signals are supplied by
the EVAL-CED1Z. The V
DD1
supply, which is the supply for the
isolated side of the device, must be supplied by an external
source via the J1-1 connector. The V
DD2
supply, which is the
supply for the nonisolated side of the device, must be supplied
by 3.3 V from an external source via the J4 connector. The board
is configured to enable the user to supply a single-ended input
signal to the V
IN
+ terminal of the ADC while the V
IN
− terminal
of the ADC is connected to GND
1
. The J10, J11, J13, and J14 links
can be modified to enable a differential signal to be applied to
the AD7400 or AD7401 inputs if required. The EVAL-AD7400/
AD7401 is configured to accept analog input signals directly
from the user’s source. Alternatively, the AD797 op amps (U2,
U3) can be used to buffer the analog input signals if required.