Methods and apparatuses to trim current limit (I.sub.p) and frequency (f) to maintain a constant maximum power. In one aspect of the invention, a power supply regulator having a peak current limit detection threshold and an operating frequency is disclosed. The peak current limit threshold or the operating frequency are adjusted specifically to maintain the I.sub.p.sup.mf.sup.n product substantially constant from one power supply controller to another where m is substantially equal to 2 and n is substantially equal to 1. In another aspect of the invention, the power supply regulator has a control circuit having a control threshold current. The peak current limit threshold or the operating frequency are adjusted specifically to maintain the product of I.sub.p.sup.mf.sup.n divided by the control threshold current substantially constant from one power supply controller to another where m is substantially equal to 2 and n is substantially equal to 1.