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TPD2S300: CC Dead battery resistor

Shinya Sawamoto
Expert 5285 points
Part Number: TPD2S300
Other Parts Discussed in Thread: TPD6S300, TPD6S300A

Hi team,

I have a couple of questions regarding the CC dead battery resistor function.
1) Does the dead battery resistor work by sourcing from CC bias when the TPD2S300 isn't supplied?
2) What is the difference of the dead battery performance between TPD2S300, TPD2S600 and TPD2S600A?
   (On the TPD2S600A datasheet, it looks to have an advantage over TPD2S600.)

Thanks in advance.
S.Sawamoto

  • 0
    TI__Mastermind 30000 points

    Hello,

    1) Below is an excerpt form the datasheet talking about the dead battery functionality of the TPD2S300

    When the USB Type-C connector is the sole power supply for a battery powered device, the device must be able to charge from the USB Type-C connector even when its battery is dead. In order for a USB Type-C power adapter to supply power on VBUS, RD pull-down resistors must be exposed on the CC pins of the sink device. These RD resistors are typically included inside a USB Type-C CC/PD controller. However, when the TPD2S300 is used to protect the USB Type-C port, the OVP FETs inside the device isolates these RD resistors in the CC/PD controller when the mobile device has no power. This is because when the TPD2S300 has no power, the OVP FETs are turned off to guarantee overvoltage protection in a dead battery condition. Therefore, the TPD2S300 integrates high voltage, dead battery RD pull-down resistors to allow dead battery charging simultaneously with high-voltage OVP protection. When the TPD2S300 is unpowered, and the RP pull-up resistor is connected from a power adaptor, this RP pullup resistor activates the RD resistor inside the TPD2S300. This enables VBUS to be applied from the power adaptor even in a dead battery condition. Once power is restored back to the system and back to the TPD2S300 on its VPWR pin, the TPD2S300 removes its RD pull-down resistor and turns on its OVP FETs within 200 µs. The amount of time the TPD2S300 does not have either its RD exposed or the PD controller's RD exposed on the CC lines is even less, around 30µs in the worst case, to minimize the probability the USB-C/PD controller in the source device interprets this as a disconnect from the sink. This way connection remains uninterrupted.

    2) I do not believe that TPD2S600 and TPD2S600A are devices in our portfolio. Would you be able to double check that you are referencing the correct device?

  • 0 in reply to Adam Mc Gaffin
    TI__Expert 5285 points

    Hi Adam,

    Thank you so much for your kind explanation for 1).
    Regarding 2), I'm sorry, it was my typo.. Allow me to ask again.

    2) What is the difference of the dead battery performance between TPD2S300, TPD6S300 and TPD6S300A?
       (On the TPD6S300A datasheet, it looks to have an advantage over TPD6S300.)

    Thanks in advance.
    S.Sawamoto

  • 0 in reply to Shinya Sawamoto
    TI__Mastermind 30000 points

    Hello,

    Those are the devices I thought you were referring to but I wanted to make sure. 

    The dead battery performance is the same between the TPD2S300 and TPD6S300. The only difference is that the TPD6S300 has more protection channels. You are right that the TPD6S300A has improved dead battery performance. These differences are explained in section 8.3.5 of the TPD6S300A datasheet. Let me know if you have any questions after reading these sections