TPS922054: Tested load output cannot drive 4A

Hi,

Our expert will check and update you soon,

Dear Sir,

Pls try below suggestions and see if there is any improvement.

(1) Change R5 to 0ohm;

(2) Change R3 to 100ohm;

(3) Change C18 to 1nF;

(4) Re-design R6 and R7 according to 

• [FAQ] How to design the UVP resistor divider for TPS922055 / TPS922054 / TPS922053 / TPS922052?

Hi Lucia,

The customer tried the suggestion you provided, but still couldn't reach 4A, at most around 3A. The current setting for the sampling resistor is 50 milliohms for the customer
Corresponding to 4A, R6, and R7, they can be completely suspended without the need for low voltage detection. Do you have any good suggestions?

Hi Vayne,

Thanks for your feedback. Not sure if we have get the information of case temperature of the device with the thermal camera?

Thank you!

BRs

Lucia

Hi Lucia,

The customer feedback is that the temperature of their chip is not very high.He doesn't have the equipment to check the temperature

Hi

Our expert will update you early next week.

Hi Vayne,

I am not sure if customer has adjusted UVP resistors. Just like the FAQ I shared, To make sure your output current won't be affected in all working condition, you should make sure (Vin_min - Vout_max) * R_UVP2 / (R_UVP1 + R_UVP2) > 1.4V. 

For example, input voltage range: 9-12.6V

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1542773/tps922052-tps922052-consultation/5956692?tisearch=e2e-sitesearch&keymatch=%25252520user%2525253A618906#

(9-7.2)*102/411k=0.45<1.4V. Besides, A rule of thumb is that you can design the sum of R_UVP1 and R_UVP2 to be around 1Mohm or 2Mohm and this normally would be a good start point.

Thank you!

BRs

Lucia