TCPP03-M20 Single Power Path

[NMartin]

Hello,

I am using the TCPP03-M20, and would like to save space/cost by combining the Source and Sink path into one mosfet gate pair.

The datasheet provides an example of a combined source/sink path using two Schottky diodes and a 1M resistor with the side effect of increasing the gate transition time to 1ms. With the voltages/currents in my application this is enough to cause the mosfets to overheat and fail.

What would you suggest for preventing this failure?

Is it possible to change the library code for this chip to allow the use of only the source path for both sourcing and sinking?

Thanks,

Nate

 

 

[NMartin]

From testing, it seems as though the consumer gate driver cannot turn on if there is no voltage on VBUS. Is this a hardware limitation of the chip?

I am thinking I can get the system to work with the following single power path layout below and some tcpp03 driver modifications.

The intent would be to turn on the provider gate driver whenever the source gate driver is on.

Feedback on the above circuit would be appreciated. Are there any hidden pitfalls with using the chip this way?

 

Thanks,

 

Nate

 

[NMartin]

It seems as though the TCPP03-M20 has a built in hardware check to prevent the consumer and provider paths to be open at the same time.

When I write 0x14 to to register 0, the ack register never updates to 0x14, but instead stays at 0x18. I have removed all software checks in the TCPP03 driver library that would prevent the consumer and provider paths being on at the same time.

Can an STM solutions engineer confirm this?

Thanks,

Nate