- 2 -

Rev. 0

EVAL-AD7707EB

LINK AND SWITCH OPTIONS

There are ten link options which must be set for the required operating setup before using the evaluation board. The functions

of these link options are outlined below.

Link No.

Function

LK1

This option selects the master clock source for the AD7707. The master clock is generated by the on-board crystal

or from an external source via SKT11. This is a double link and both links must be moved together for the correct

operation of the evaluation board.

With both links in position "A", the external clock option is selected and an external clock applied to SKT11 is

routed to the MCLKIN pin of the AD7707.

With both links in position "B", the on-board crystal is selected to provide the master clock to the AD7707.

LK2

This link is used to select the on-board reference.

With this link in position "A", the AD780 is selected as the on-board reference. This provides a 2.5V

reference

which is suitable for the AD7707 operating at +5V.

With this link in position "B", the AD589 is selected as the on-board reference. This provides a 1.23V

reference

which is suitable for the AD7707 operating at +3V.

LK3

This link is used to select the reference source for the REFIN(-) input of the AD7707.

With this link in position"A", the REFIN(-) pin is connected directly to AGND.

With this link in position "B", the REFIN(-) pin is connected to SKT10. An external voltage applied to SKT10

can now be used as the REFIN(-) for the AD7707.

LK4

This link is used to select the reference source for the REFIN(+) input of the AD7707.

With LK4 in position "A", the REFIN(+) pin is connected to the output of the on-board reference.

With LK4 in position "B", the REFIN(+) pin is connected to SKT9. An external voltage applied to SKT9 can

now be used as the REFIN(+) for the AD7707.

LK5

This link is in series with the AIN1 input of the AD7707.

With this link in place, an analog input signal applied to SKT3 is routed directly to the AIN1 pin of the AD7707.

This link may be removed

so that the user can add signal conditioning circuitry if required.

LK6

This link is in series with the AIN2 input of the AD7707.

With this link in place, an analog input signal applied to SKT4 is routed directly to the AIN2 pin of the AD7707.

This link may be removed

so that the user can add signal conditioning circuitry if required.

LK7

This link is in series with the AIN3 input of the AD7707.

With this link in place, an analog input signal applied to SKT5 is routed directly to the AIN3 pin of the AD7707.

This link may be removed

so that the user can add signal conditioning circuitry if required.

LK8

This link is used to select the common input for low level input channels (AIN1 and AIN2).

With this link in position "A", the LCOM input is tied to AGND.

With this link in position "B", the LCOM input is tied to VREF.

With this link in position "C", the LCOM input is set to a voltage applied to SKT6.

LK9

This link is connected to the HBIAS pin. It used to signal condition the high level input channel (AIN3).

With this link in positoin "A", the HBIAS pin is tied to the REFIN+ pin of te AD7707.

With this link in position "B", a voltage applied to SKT7 is applied to the HBIAS pin.

LK10

This link is connected to the HCOM pin of the AD7707. It stes the common input voltage for the high level input

channel (AIN3).

With this link in position "A", the HCOM input is tied to AGND.

With this link in position "B", the HCOM input is tied to VREF.

With this link in position "C", the HCOM input is set to a voltage applied to SKT8.