TPS51285A: TPS51285A ----- Output capacitor of VREG3 and VREG5

Hi Chin,

We would suggest to keep 4.7uF. The capacitance is required by the internal LDO to keep it stable in any normal operating condition. I think your measurement only covered a few specific conditions. The LDO may still be unstable at conditions such as doing load transient.

Also, DC-bias derating should be considered with MLCC. You effective capacitance can be even less than 1uF.

Regards,

Hao

Hi Hao,

Thanks for your comment.

By the way, I am debuging an issue of damage High-Low side MOSFET (CSD87331Q3D) of switching2 output 3.3V with TPS51285A circuit , the CSD87331Q3D seems short through to ground.

Is the issue possible relevant to unstable VREG3? (With 1uF capacitor)

Sincerely,

Chin

Hi Hao,

Thanks for your comment.

By the way, I am debuging an issue of damage High-Low side MOSFET (CSD87331Q3D) of switching2 output 3.3V with TPS51285A circuit , the CSD87331Q3D seems short through to ground.

Is the issue possible relevant to unstable VREG3? (With 1uF capacitor)

Sincerely,

Chin