question about TPS51123A

The system current can't get higher than 3A, both the 3.3V and the 5V chanel. My high side MOSFET is IRF7821, low side MOSFET is FDS6690AS and the inductance is 4.7uH.

Yao Chen,

1. What's the input voltage? it's should be larger than 5.5V anytime.

2. What.s the saturation current of the inductor? and what's the part number of Inductor?

Vin=18V,I(sat)=18A,I(rms)=10A,part number is FEPI 1004H-4R7M-K01(made by tai teck).In addtion,my overcurrent setting is big enough.And I also have a Schottky diode in parallel with the low side MOSFET.

能否将您的真实电路图以附件的形式传上来，输入电路图确实看不清楚。

通常而言，输出电流受限都是因为过电流保护造成的，所以一定是电路中某些细节造成了过电流的异常。