EVAL-AD7707EB Datasheet, PDF (2/16 Pages) Analog Devices – Evaluation Board for the AD7707 3V/5V, +/-10V Input Range, 1mW, 3Channel, 16-Bit, Sigma Delta ADC

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.
LK1
LK2
LK3
LK4
LK5
LK6
LK7
LK8
LK9
LK10
Function
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.
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
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
which is suitable for the AD7707 operating at +3V.
reference
reference
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.
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.
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.
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.
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.
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.
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.
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.
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