Analog Devices EVAL-AD7715-5EB Instructions Manual page 3

Setup Conditions
Table I shows the position in which all the links are set when the
evaluation board is sent out.
Table I. Initial Link Positions
Link No. Position Function.
LK1 B Both links in position B to select the
on-board crystal oscillator as the master
clock for the board.
LK2 A REF IN(-) connected directly to
AGND.
LK3 A REF IN(+) connected to the output of
the on-board AD780 reference.
LK4 C Selects AD780 as the voltage reference.
LK5 IN Connects input signal from SKT3
directly to the AIN(+) pin of the
AD7715.
LK6 IN Connects input signal from SKT4
directly to the AIN(-) pin of the
AD7715.
EVALUATION BOARD INTERFACING
Interfacing to the evaluation board is either via a 9-way D-Type
connector, SKT1, or a 36-way Centronics connector, SKT2.
The pinout for the SKT1 connector is given in Figure 1 and its
corresponding pin designations are given in Table II. The
pinout for this SKT2 connector is shown in Figure 2 and its pin
designations are given in Table III. The evaluation board should
be powered up before a cable is connected to either of the
connectors.
SKT2 is used to connect the evaluation board to the printer
port (parallel port) of a PC. Connection between the two is
direct via a standard parallel printer port cable. SKT1 is used to
connect the evaluation board to any other system.
REV. A
1
6
Figure 2. SKT1 Pin Configuration
Table II. SKT1 Pin Designations
1 SCLK Serial Clock. The signal on this pin is buffered
before being applied to the SCLK pin of the
AD7715.
2 DRDY Logic Output. This is a buffered version of the
signal on the AD7715's DRDY pin.
3 CS Chip Select. The signal on this pin is buffered
before being applied to the CS pin of the
AD7715.
4 RESET Reset Input. The signal on this pin is buffered
before being applied to the RESET pin of the
AD7715.
5 DIN Serial Data Input. Data applied to this pin is
buffered before being applied to the AD7715's
DIN pin.
6 DGND Ground reference point for digital circuitry.
Connects to the DGND plane on the evaluation
board.
7 DOUT Serial Data Output. This is a buffered version of
the signal on the AD7715's DOUT pin.
8 DV Digital Supply Voltage. The DV
DD
the evaluation board can be supplied via this pin
provided no voltage is applied to the main DV
terminal.
9 NC No Connect. This pin is not connected on the
evaluation board.
NOTE
1
An explanation of the AD7715 functions mentioned here is given in Table III as
part of the SKT2 pin designations description.
–3–
EVAL-AD7715-5EB
2 3 4
5
7 8 9
1
voltage for
DD
DD