Part Number: PT4201
PT4201 is a highly integrated current mode PWM controller，providing low standby power and cost
effective system solution for the sub 30W flyback converter applications. It is also suitable for high
precision and high reliable LED lighting applications.
It features power saving operation at no load or light load condition, PWM frequency is reduced to minimize
switching loss and low standby power and high efficiency is thus achieved. PT4201 also features low
VDD startup current which also contributes to low standby power. The built in LEB on the current sense
input removes the signal glitch due to snubber circuit diode reverse recovery thus reduce the external
component count and system cost in the design. Rich protection is implemented in PT4201 including
cycle-by-cycle current limiting (OCP), over load protection (OLP), VDD over voltage clamp and under
voltage lockout (UVLO). Gate drive output is clamped at 18V to protect the power MOSFET. By limiting the
minimum frequency above 22 kHz eliminates the potential audible noise when the system works under
light or no load conditions.
Excellent EMI performance is achieved with C.R.PowTech proprietary frequency Jittering technique
together with soft driving control at totem pole gate drive output.