TPS53119: Parameter validation

Anna 

Anna said:

Does the output capability of this controller depend on the parameters of the external mos?

Yes.  The output current capability of any controller with external MOSFETs will depend on the selected external MOSFETs

Anna said:

If engineer want to see the output can do how much current, need see which parameters?

I apologize anna, I am not sure I understand your question.

TI recommends the TPS53119 controller to be used in applications with maximum loading currents upto 20A based on the strength of it's MOSFET drivers and the balance of Rds_on and Qgate for MOSFETS that were available when the TPS53119 was developed and released.  Newer MOSFETs with a better Rds_on x Qg figure of merit released since the release of the TPS53119 may increase this slightly, but the ability of the TPS53119 to delivery current depends on the external MOSFETs selected.

MOSFETs should be selected to balance the Rdson conduction losses as well as driver and switch transition losses.  Selection of MOSFETs with gate charge greater than 50nC may negatively affect device operation.

The TPS53119 has a programmable current limit, set by the selection of the Rtrip and the GND to SW drop across the low-side MOSFET during the low-side conduction time.  The equation for the programmable current limit is provided in the datasheet.

Additionally, the current handling capabilities of a design using the TPS53119 may be limited by the thermal power capabilities of the MOSFETs selected, including their Rdson, switching losses, and thermal power dissipation capabilities.

Hopefully that helps answer your question.