MC33063A: I mainly want to inquire about the derivation process of the output current of the boost circuit and simplify the Q1 and Q2 drive issues in the schematic diagram

liujun

Part Number: MC33063A

Tool/software:

Some questions are as follows:
1. How is the output current derived in a boost circuit?
2. Are Q1 and Q2 in the step-down circuit a composite Darlington structure?
3. May I ask if the input voltage of a similar driving method in the BUCK circuit can exceed 100V without considering the withstand voltage issues of Q1 and Q2? (I want to learn from this driving method and use F28035 to make a digital high-voltage BUCK)
thank you!

3 months ago

+1 Brigitte 3 months ago

TI__Guru 61195 points

Hello liujun,

1. The output current is normally commanded by the application that shall be supplied by the converter. For more details, please have a look at this app note: Basic Calculation of a Boost Converter's Power Stage (Rev. D)

2. Q1 and Q2 are forming in every topology a Darlington structure.

3. MC33063A has a hysteretic type of controller. I do not expect that this is easy to be implemented in a digital solution.

Best regards,
Brigitte

0 liujun 3 months ago in reply to Brigitte

Prodigy 240 points

Thank you for your answer

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MC33063A: I mainly want to inquire about the derivation process of the output current of the boost circuit and simplify the Q1 and Q2 drive issues in the schematic diagram