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[FAQ] TPS65381A-Q1: Can the VDD1_SENSE pin be used to monitor another regulator output if VDD1 LDO controller isn't used in the application?

Part Number: TPS65381A-Q1

For several reasons various applications may need to use a regulator that isn't integrated in the TPS65381A-Q1 or the VDD1 LDO controller with external FET.  Once example would be to support MCU's that require higher core current than is possible with the LDO architectures due to the high current which drives the need for high efficiency for electrical and thermal reasons. 

Can the VDD1_SENSE pin be used to monitor another regulator output if VDD1 LDO controller isn't used in the application?

Best Regards,

Scott Monroe

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For more information on Multi-Channel Power Management ICs: 

Find the right power solution for your processor or FPGA. Visit www.ti.com/SoCPower today!

  • Yes, the VDD1 LDO controller of the TPS65381A-Q1 may be re-purposed and used as a voltage monitor for different regulator that is not integrated into the TPS65381A-Q1 if the VDD1 LDO controller isn't used in the application.

     

    The VDD1_SENSE pin may be used to monitor the output from the other regulator and the VDD1_G (gate drive pin may be left floating). The VDD1_UV and OV flags and device reactions will occur the same as if the VDD1 LDO controller is being used with an the external FET to generate the output voltage for the VDD1 regulation. The target sense voltage for VDD1_SENSE is 0.8V. The software must ensure NMASK_VDD1_UV_OV is set to 1 while the TPS65381A-Q1 is in DIAGNOSTIC state to enable the UV and OV monitoring function so a detected VDD1 UV event will cause the TPS65381A-Q1 to transition to its RESET state, pulling the NRES pin and thus the MCU reset bus low and causing ENDRV pin (safing output) to also be driven low during a UV or OV event on the VDD1_SENSE pin. Please note the resistor tolerance used for the resistor divider for the voltage monitoring will impact the UV and OV monitoring tolerance.

     

    Attached is a PDF outlining several different options and power tree topologies. Two of these concepts have been implemented in TI Designs with the TPS65381A-Q1 device.

     

    4456.2017-02-03 TPS65381A-Q1 with External DCDC.pdf

     

    TI Designs: TIDA-01537, Scalable Automotive HEV/EV 6s to 96s Lithium-Ion Cell

    Supervision Demonstrator Reference Design

    TPS653851A-Q1 uses VDD1_SENSE to monitor the core rail generated by the TPS57160-Q1 for a TMS570LS0432 MCU.

     

    TI Designs: TIDA-00548, 4-20mA Analog Input Module Reference Design for Safety Applications

    TPS653851A-Q1 uses VDD1_SENSE to monitor the core rail generated by the TPS62170 for a RM41L232 MCU.

     

    Best Regards,

    Scott Monroe

    --------------------------------------------------

    For more information on Multi-Channel Power Management ICs: 

    Find the right power solution for your processor or FPGA. Visit www.ti.com/SoCPower today!