Texas Instruments ADS8688EVM-PDK, Руководство пользователя

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Power Supplies
4 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.
CAUTION
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.
Table 9 provides jumper settings for generating HVDD
and HVSS using the onboard switching regulator U9.
Table 9. Jumper Settings for Generating HVDD and HVSS Using an Onboard Switching Regulator
Jumper Position for Using an Onboard Switching Regulator
J12 Closed between pins 1 and 2
J14 Closed between pins 1 and 2
J17 Open
HVDD and HVSS for buffers U4 and U5 can also be generated by providing external high-voltage supplies
on J18, as shown in
Table 10 . Table 11 and Figure 3 illustrate the power-supply connections for external
supplies.
Table 10. Jumper Settings for Generating HVDD and HVSS from External High-Voltage Supplies
Jumper Position for Generating HVDD and HVSS from External Voltage Supplies
J12 Closed between pins 2 and 3
J14 Closed between pins 2 and 3
J17 Closed
Table 11. Power-Supply Connections
Voltage Voltage
Supply Signal Range Pin Number Note
Required only for generating HVDD and HVSS using the
External 5 V EXT_5V 5 V to 5.5 V J32.2
onboard switching regulator
— GND GND J32.1 —
Required only for generating HVDD and HVSS from external
External HVDD EXT_HVDD 16 V to 25 V J18.3
high-voltage supplies
Required only for generating HVDD and HVSS from external
External HVSS EXT_HVSS –16 V to –25 V J18.1
high-voltage supplies
— GND GND J18.2 —
9 SBAU230A – August 2014 – Revised December 2014 ADS8688EVM-PDK Evaluation Module
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