The composition of switching power supply control chip
The switching power supply control chip is a kind of chip in the switching power supply. Before the advent of the switching power supply, it was a linear power supply.
The switching power supply is a high-efficiency and energy-saving power supply, and it is also the mainstream of the current power supply development. The key internal components work in a high-frequency state, and are constantly on and off. The switching power supply comes from this, and the power efficiency is as high as 70%-90%. , nearly double the efficiency of standard linear regulated power supplies.
The switching power supply circuit is relatively complex, mainly composed of the following six parts:
1. EMI input filtering: here is low-pass filtering to prevent high-frequency signals from passing through, and two-stage EMI filtering is adopted if necessary;
2. Rectification and filtering: After the mains passes through the bridge, the direct current is output and filtered by the capacitor to obtain a relatively clean direct current;
3. Main switch conversion circuit: when isolation is required, there is generally a transformer;
4. Control circuit: This includes oscillator, reference voltage source, error amplifier, etc.;
5. Feedback circuit: This includes voltage and current feedback
6. Output filtering.
Among them, the control circuit is the core of the whole, and the switching power supply control chip is the core component of the control circuit.
