How to design system compensation for boost converter

“Boost converter is the most important converter topology circuit in switching power supply, and is widely used in the development of switching power supply products. In this paper, the Boost converter will be taken as an example to describe the design formula and steps of the compensation link of the current mode control system in detail.

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Boost converter is the most important converter topology circuit in switching power supply, and is widely used in the development of switching power supply products. In this paper, the Boost converter will be taken as an example to describe the design formula and steps of the compensation link of the current mode control system in detail.

1: Topological block diagram of current mode Boost converter

Two: Boost control system compensation link design example

This system will use Type II error amplifier to design the current-mode Boost compensation link.

Design steps:

1. Choose the appropriate resistor RFBT according to the bias current and power loss;

2. Calculate D’ according to the input and output voltage;

3. Calculate Ri according to the sampling resistance and current;

4. Calculate the transconductance Gm;

5. Calculate the frequency of the right half-plane zero (RHPZ) based on the minimum input voltage and maximum load current;

6. According to the RHPZ, set the target bandwidth:

7. Calculate the IF gain AVM based on the target bandwidth

8.Set Wzea to 1/10 target cutoff frequency

9.Set WHF to the lesser of RHP and ESR zero frequency

Design formula:

Three: Compensation results