EVAL-AD7899CB Datasheet, PDF (2/12 Pages) –

EVAL-AD7899CB
Link and Switch Options
There are 9 link options which must be set for the required operating setup before using the evaluation board. The
functions of these options are outlined below.
Link No. Function.
LK1
LK2
LK3
LK4
LK5
This link option selects the input range of the ADC. The position of this link is determined by the input
range required by the user. Please refer to the AD7899 data sheet for more information.
When this link is in position "A" V_INB is connected to V_INA.
When this link is in position "B" V_INB is connected toAGND.
This link selects the reference source for the AD7899.
When a link is in position "A" the AD780 is selected as the reference source.
When a link is in position "B" an external voltage applied to SK7 is selected as the reference source.
When the link is removed completly the internal reference of the AD7899 is used as the reference source.
This link selects the source of the +12V supply.
When this link is in position "A" an external +12V must be connected to J2-1.
When this link is in position "B" the EVAL-BOARD CONTROLLER will provide the +12V supply
This link selects the source of the VDD supply.
When this link is in position "A" an external +5V must be connected to J2-2.
When this link is in position "B" the EVAL-BOARD CONTROLLER will provide the +5V supply
This link selects the source of the -12V supply.
When this link is in position "A" an external -12V must be connected to J2-4.
When this link is in position "B" the EVAL-BOARD CONTROLLER will provide the -12V supply
LK6
LK7
LK8
LK9
This link selects the source of the V_DRIVE supply.
When this link is in position A the VDD supply is used as the V_DRIVE supply.
When this link is in position B the DVDD supply of the EVAL-BOARD CONTROLLER is used as the
V_DRIVE supply.
When this link is in position C an external supply on SK6 is used as the V_DRIVE supply.
This link is used to select the source of the Conversion Start signal.
When this link is in position "A" the CONVST signal is generated by the EVAL-BOARD CONTROL-
LER.
When this link is in position "B" the CONVST signal is generated by an external signal connected to SK2.
This link selects the source of the CLKIN signal for the AD7899.
When this link is in position "A" the CLKIN signal is provided by the EVAL-BOARD CONTROLLER.
When this link is in position "B" the CLKIN signal can be provided by a signal applied to SK3. If no
signal is applied to SK3 the pin is pulled low and the internal oscillator is is used to control the conver-
sion.
This link sets the logic level of the STBY pin.
When a link is in position "A" the STBY pin is controlled by the FL1 flag pin of the EVAL-BOARD
CONTROLLER.
When a link is in position "B" the STBY pin is tied to VDD and the part is in normal operating mode.
When a link is in position "C" the STBY pin is tied to DGND and the part is in standby mode.
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