Switching power supply from the high-speed switching power supply controller M62213FP

Figure (a) illustrates a block diagram of the internal architecture of the M62213FP, which is a high-speed switching power supply controller. This device includes an oscillator, PWM comparator, error amplifier, output circuit, over-voltage protection, timing latch circuit, over-current protection circuit, and a soft-start circuit. It operates at a switching frequency of 700 kHz, with a peak output current of 1 A. The push-pull output circuit exhibits a very low initial current, typically 130 µA. The starting voltage is set at 12.5 V, while the stop voltage is 8.3 V, which aids in reducing the size of the input smoothing capacitor. Integrated features include high-speed current limiting, overvoltage protection, timed lockout, dead-time control, and soft-start functionality. The feedback mechanism utilizes an optocoupler with direct excitation from the error amplifier output to prevent malfunctions in low-voltage operating conditions. The circuit can achieve a highly functional switching power supply with minimal external components. Figure (b) depicts the configuration of the high-speed switching power supply controller as designed with the M62213FP. The duration of the power output pulse is determined by a resistor connected to the SOFT pin. If a capacitor is placed in parallel with this resistor, the start time is extended, facilitating a soft start. The M62213FP operates at its specified starting voltage, with R1 rectifying the voltage supplied by the AC power source. During normal operation, a winding from the flyback transformer provides a rectified voltage through the rectifier diode VD, proportional to the output voltage, and is used for feedback control and overvoltage detection. To mitigate malfunctions caused by noise, a noise filter is created using RNF and CNF.

The M62213FP is designed for high efficiency and reliability in power supply applications. The internal oscillator generates a clock signal that drives the PWM comparator, which modulates the output voltage based on feedback from the error amplifier. The error amplifier compares the output voltage to a reference voltage and adjusts the duty cycle of the PWM signal to maintain a stable output. The over-voltage protection circuit monitors the output voltage and disables the switching operation if the voltage exceeds a predetermined threshold, ensuring the safety of connected components.

The timing latch circuit plays a crucial role in controlling the switching operation, providing a defined period during which the output can respond to changes in load conditions. The over-current protection circuit limits the output current to prevent damage to the power supply and connected devices. The soft-start feature gradually increases the output voltage during startup, reducing inrush current and minimizing stress on the components.

The design of the M62213FP allows for flexibility in application, with the ability to adjust the output voltage and current characteristics through external components. The integration of noise filtering components enhances the stability of the power supply, making it suitable for sensitive electronic devices. Overall, the M62213FP is an effective solution for high-speed switching power supply applications, combining advanced features with ease of implementation.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.