Maximum LDO output current?

[ilikebbs]

some IC claims that LDO controller is integrated. One output pin is used to control external MOSFET to generate low voltage. so what is the main factor to determine the maximum output current of LDO? Thanks.

ilikebbs

 

[rhaynes]

That external MOSFET is used as the final pass element. So the final current will depend on the current rating (size) of the MOSFET but there are limits to the choices of the MOSFET. The loop stability is affected by the MOSFET gate capacitance and gain. The manufacturer probably has some recommendations for the parts and you need to stay near them in terms of gate capacitance and gain which is very closely related to the max current rating of the MOSFET.

Ray

 

[nxtech]

The final determining factor current capability for a LDO is the pass element whether its a BJT or MOSFET.