Power Supplies - Texas Instruments ADS8688EVM-PDK User Manual

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Power Supplies

The ADS8688EVM can be powered from the Simple Capture card if onboard buffers for active low-pass
filters are not being used and the onboard regulator (U9) for generating high-voltage supplies (HVDD and
HVSS) is disabled by closing jumper J17. The HVDD and HVSS supplies are only required for buffers U4
and U5.
Do not open jumper J17 if the ADS8688EVM must be powered only from the
Simple Capture card and an external 5-V supply is not provided on J32.
High-voltage supplies (HVDD and HVSS) for buffers U4 and U5 can be generated using the onboard
regulator (U9) if an external 5-V dc supply is provided on J32. The external 5-V dc supply must be at least
200 mV above the unregulated 5-V supply of the Simple Capture card. The external 5-V dc supply must
be capable of providing at least 500 mA of current.
and HVSS using the onboard switching regulator U9.
Table 9. Jumper Settings for Generating HVDD and HVSS Using an Onboard Switching Regulator
Jumper
J12
J14
J17
HVDD and HVSS for buffers U4 and U5 can also be generated by providing external high-voltage supplies
on J18, as shown in
supplies.
Table 10. Jumper Settings for Generating HVDD and HVSS from External High-Voltage Supplies
Jumper
J12
J14
J17
Voltage
Supply Signal
External 5 V EXT_5V
—
External HVDD EXT_HVDD
External HVSS EXT_HVSS
—
SBAU230A – August 2014 – Revised December 2014
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Table 10. Table 11 and
Position for Generating HVDD and HVSS from External Voltage Supplies
Table 11. Power-Supply Connections
Voltage
Range Pin Number
5 V to 5.5 V
GND GND
16 V to 25 V
–16 V to –25 V
GND GND
Copyright © 2014, Texas Instruments Incorporated
CAUTION
Table 9 provides jumper settings for generating HVDD
Position for Using an Onboard Switching Regulator
Closed between pins 1 and 2
Closed between pins 1 and 2
Open
Figure 3 illustrate the power-supply connections for external
Closed between pins 2 and 3
Closed between pins 2 and 3
Closed
Required only for generating HVDD and HVSS using the
J32.2
onboard switching regulator
J32.1 —
Required only for generating HVDD and HVSS from external
J18.3
high-voltage supplies
Required only for generating HVDD and HVSS from external
J18.1
high-voltage supplies
J18.2 —
ADS8688EVM-PDK Evaluation Module
Power Supplies
Note
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