Switching power supply from the high-speed switching power supply controller M62213FP
Figure (a) shows a block diagram of the internal structure of the M62213FP. M62213FP is a high speed switching power supply controller. It consists of an oscillator, PWM compar
ator, error amplifier, the output circuit, over-voltage protection and the timing of the latch circuit, over-current protection circuit and soft-start circuit. Switching frequency of 700kHz, the peak output current of 1A, push-pull output circuit, before the start of the current circuit is very small, typically 130 A, beginning with the start-stop voltage difference is large, starting starting voltage is 12.5V, start stop voltage of 8.3V, this would reduce the input smoothing capacitor. On-chip high-speed current limiting, overvoltage and timed lockout, dead-time control and soft start, optocoupler feedback with direct excitation of the error amplifier output to prevent malfunction at low voltage functional circuits. Few external components can constitute function more perfect switching power supply.Figure (b) by high-speed switching power supply switching power supply controller configured as shown M62213FP. The power output pulse on-time is determined by the resistor connected to the SOFT side, if a capacitor in parallel with this resistance, the start-time increases, so that you can achieve a soft start. M62213FP itself at start operating voltage, R1 is rectified by a voltage provided by the AC power source; normal operation from the flyback transformer of a winding to provide rectified by the rectifier diode VD, a voltage proportional to the output voltage at this time, therefore, also used for feedback control and overvoltage detection. To prevent malfunction due to noise, filter access RNF and CNF constituted noise filtering.