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TPS65219: Power consumption & Thermal

austin.chen
Prodigy 200 points
Part Number: TPS65219
Other Parts Discussed in Thread: AM623,

Hi, TI

Since we need to program eFuse AM623, it should work under DFU mode.

So we use PMIC, TPS6521904RHBR,  to have default 0.85V VDD_CORE.

But TPS6521904RHBR LDO output 1.8V as default and we can't use it for   VDDR_CORE.

That means that we can't decrease VDD_CORE to 0.75V to mitigate our thermal issue.

Do you have PMIC that Buck1 and LDO2 both output 0.85V as default?

  • 0
    TI__Mastermind 22421 points

    Hi Austin,

    Thank You for using E2E. We do not have any PMIC NVM variant with a Buck and an LDO configured to output 0.85V. The reason is because VDD_CORE and VDDR_CORE are expected to be powered by the same source so they ramp together when VDD_CORE is operating at 0.85V. This last statement is noted in the AM62x data sheet. When using TPS6521904, both VDD_CORE and VDDR_CORE must be supplied by the PMIC Buck1. 

    Why would you need to change the voltage on Buck1? Could you provide more information on this? The AM62x processor doesn't support dynamic voltage scaling and the 1.8V VPP rail for eFuse is supplied by a discrete LDO (external to the PMIC). Here is more information on the VDD_CORE voltage selection:

    https://www.ti.com/lit/an/slvafd0b/slvafd0b.pdf

    Thanks,

    Brenda

  • +1 in reply to Brenda Diaz
    Prodigy 200 points

    Hi, Brenda

    Since we have thermal issue with AM623, we try to minimize the power consummption to mitigate this issue. It's better to use 0.75V Core voltage to reduce power consumption. But we also need to burn eFuse with DFU mode, DFU mode only support 0.85V Core voltage. If AM623 dones't support dynamic voltage scaling, can we setup this voltage by HW pin? 

  • 0 in reply to austin.chen
    TI__Mastermind 22421 points

    Hi Austin,

    Since AM62x doesn't support dynamic voltage scaling, we have a different TPS65219 orderable part number to support each VDD_CORE voltage. TPS6521904 can be used for 0.85V and TPS6521903 can be used for 0.75V.

    Additionally, I have checked with the Sitara processor team about the CORE requirements for USB DFU backup up. They have done the required analysis to confirm 0.75V on VDD_CORE works for DFU. Let us know if you see any issues.  

    Thanks,

    Brenda