TOP221PN Off-line PWM Switch IC

TOPSwitch-II family introduced by Power Integrations designed as the latest generation of its industry-leading TOPSwitch series of off-line switcher ICs.  It is basically a complete integrated circuit consisting of only three pins with all functionalities for an off-line switched mode control system. These are high voltage N-channel power MOSFET featuring controlled turn-on gate driver, voltage mode PWM controller with integrated 100 kHz oscillator, high voltage start-up bias circuit, bandgap derived reference, bias shunt regulator/error amplifier for loop compensation and fault protection circuitry. This brings TOPSwitch technology advantages to many new applications, i.e. TV, Monitor, Audio amplifiers, etc.

Meanwhile, it improves the efficiency, productivity and offers high reliability for the device. TOP221PN Off-line PWM Switch IC designed explicitly for use in 100/115/230 VAC off-line Power Supply applications in the 100 to 150 W range.  And also for 85-265 VAC off-line power factor correction (PFC) applications in the 50 to 90 W range.

TOPSwitch designed as a self biased and guarded linear control current-to-duty cycle converter with an open drain output. This IC acheives High efficiency through the utilization of CMOS and integration of the utmost number of functions possible. The CMOS significantly reduces bias currents as compared to bipolar or discrete solutions. Moreover, the Integration eliminates external power resistors utilized for current sensing and/or supplying initial start-up bias current. During normal operation, the interior output MOSFET duty cycle linearly decreases with increasing CONTROL pin current. To implement all the specified control, bias, and protection functions, the DRAIN and CONTROL pins each perform several functions.