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AM4376: About PMIC TPS65218 Design issue

yimin bai34
Genius 4755 points

Part Number: AM4376
Other Parts Discussed in Thread: TPS65218, , TPS62660, TPS62802

Hi SIr 

We used AM4376 with TPS65218 for design.

We want to connect VDDSHV1/V2/V3/V5/V6/V7/V8 to LDO1 of TPS65218 and found it is over the limit current.(400mA)

Power Name

Current(mA)

VDDS

70

VDDSHV1

30

VDDSHV2

80

VDDSHV3

100

VDDSHV5

10

VDDSHV6

50

VDDSHV7

10

VDDSHV8

50

VDDS_SRAM_CORE_BG

10

VDDS_SRAM_MPU_BB

10

VDDS_PLL_DDR

10

VDDS_PLL_CORE_LCD

20

Total

450

1. We want to add one TPS62660 to connect to above pin to increase current . Does it have any risk or suggestion?

2. Does TI have another suggestion for above request ?

BR

Yimin

  • 0
    TI__Genius 13567 points

    Hi Yimin,

    It looks like you can use GPIO1 from the TPS65218 to drive the EN signal on an external device (see figure 4 of the PMIC user guide). The GPIO1 follows the LDO1 power sequencing so you can use an external device to supplement the LDO1 supply. If you do this please keep analog supplies on the LDO and move the VDDSHVx (1.8V) supplies to the TPS62660. Anything else on your board that connects to the 1.8V I/Os on the AM437x will also need to be powered by the TPS62660 and not the LDO1.

    I don't have a recommendation on a specific TPS part for your design. It appears that the TPS62660 part is a standard DCDC converter and it will work for your purposes.

    Regards,
    Ahmad

  • 0
    TI__Guru**** 152430 points
    Hi Yimin,

    Yes, TPS62660 can make your 1.8V. And TPS62802 is much smaller, while TPS6208818 offers a PG output.
  • 0 in reply to Chris Glaser
    Genius 4755 points

    Hi Sir

    Do you have any suggestion which pin must be powered by LDO1 if we use external 1.8v power supply.

    BR

    Yimin

  • 0 in reply to yimin bai34
    TI__Genius 13567 points

    The supplies with "VDDA", PLL, and OSC in the name are typically powered by an LDO in order to help reduce noise compared to a DCDC converter. The other supplies are inputs for internal LDOs and can be powered by a DCDC converter. 

  • 0 in reply to Ahmad_Rashed
    TI__Genius 9655 points
    Here is our recommendation:

    The below group of supplies should be powered by LDO1
    - VDDS_SRAM_CORE_BG
    - VDDS_SRAM_MPU_BB
    - VDDS_PLL_DDR
    - VDDS_PLL_CORE_LCD
    - VDDS_OSC
    - VDDA_ADC
    - VDDA_1P8V_USB0/1

    Following supplies can be powered by the external regulator
    - VDDS
    - VDDSHVx

    Please make sure you follow all the power supply sequencing requirements including power-up/down. It is recommended that VDDS be the first supply to power-up and last supply to power-down (which in your case is the VDDS/VDDSHVx group)

    Regards, Siva