Datasheet

EVAL-AD7265/AD7266
Rev. 0 | Page 6 of 24
Link No. Description
LK31 This link option adds a 50 Ω termination to AGND at the V1 DIFF socket (J17) for differential operation.
This link is removed when using the single-ended-to-differential converter.
When this link is inserted, a 50 Ω termination is added to the input signal applied to VI DIFF socket (J17). This link should be
inserted if this circuit is not being used to ground the input to U5-B.
LK32 and
LK34
These link options are used in conjunction with each other to set up the AD8022 (U5) dual op amp configuration to convert
either a bipolar or unipolar single-ended signal into a differential signal centered on the common-mode voltage.
Both links should be closed when the bipolar analog input signal biased around 0 V is applied to J17.
Both links should be open when a unipolar analog input biased around 2.5 V is applied to J17.
LK32 should be closed when this circuit is not being used.
LK33 This link option selects the common-mode voltage applied to U5-A, the AD8022 dual op amp configuration used to perform
single-ended-to-differential conversion on the analog input.
In Position A, an external common-mode voltage can be applied to U5-A via J18.
In Position B, the +V
S
input to the AD8022 is tied to AGND, in which case the AD8022 dual op amp is not used.
In Position C, a portion of V
REF
is applied to U5-A to set up the common-mode voltage.
LK35 Not populated.
LK36 This link option adds a 50 Ω termination to AGND at the V2 DIFF socket (J19) used for differential operation.
This link is removed when using the single-ended-to-differential converter.
When this link is inserted, a 50 Ω termination is added to the input signal applied to the V2 DIFF socket (J19). This link should be
inserted if this circuit is not being used to ground the input to U6-B.
LK37 and
LK39
These link options are used in conjunction with each other to set up the AD8022 (U6) dual op amp configuration to convert
either a bipolar or unipolar single-ended signal into a differential signal centered on the common-mode voltage.
Both links should be closed when the bipolar analog input signal biased around 0 V is applied to J19.
Both links should be open when a unipolar analog input biased around 2.5 V is applied to J19.
LK39 should be closed when this circuit is not being used.
LK38 This link option selects the common-mode voltage applied to U6-A, the AD8022 dual op amp configuration used to perform
single-ended-to-differential conversion on the analog input.
In Position A, an external common-mode voltage can be applied to U6-A via J19.
In Position B, the +IN input is tied to AGND, in which case the AD8022 dual op amp is not used.
In Position C, a portion of V
REF
is applied to U6-A to set up the common-mode voltage.
LK40 Not populated.
LK41 This link option adds a 50 Ω termination to AGND at the V3 DIFF socket (J20) for differential operation.
This link is removed when using the single-ended-to-differential converter.
When this link is inserted, a 50 Ω termination is added to the input signal applied to the V3 DIFF socket (J20). This link should be
inserted if this circuit is not being used to ground the input to U7-B.
LK42 and
LK44
These link options are used in conjunction with each other to set up the AD8022 (U7) dual op amp configuration to convert
either a bipolar or unipolar single-ended signal into a differential signal centered on the common-mode voltage.
Both links should be closed when the bipolar analog input signal biased around 0 V is applied to J20.
Both links should be open when a unipolar analog input biased around 2.5 V is applied to J20.
LK42 should be closed when this circuit is not being used.
LK43 This link option selects the common-mode voltage applied to U7-A, the AD8022 dual op amp configuration used to perform
single-ended-to-differential conversion on the analog input.
In Position A, an external common-mode voltage can be applied to U7-A via J21.
In Position B, the +IN input is tied to AGND, in which case the AD8022 dual op amp is not used.
In Position C, a portion of V
REF
is applied to U7-A to set up the common-mode voltage.
LK45 Not populated.
LK46 This link option adds a 50 Ω termination to AGND at the V4 DIFF socket (J22) for differential operation.
This link is removed when using the single-ended-to-differential converter.
When this link is inserted, a 50 Ω termination is added to the input signal applied to the V4 DIFF socket (J22). This link should be
inserted if this circuit is not being used to ground the input to U8-B.
LK47 and
LK49
These link options are used in conjunction with each other to set up the AD8022 (U8) dual op amp configuration to convert
either a bipolar or unipolar single-ended signal into a differential signal centered on the common-mode voltage.
Both links should be closed when the bipolar analog input signal biased around 0 V is applied to J22.
Both links should be open when a unipolar analog input biased around 2.5 V is applied to J22.
LK47 should be closed when this circuit is not being used.