(Transistor + MOS) & (MOS + MOS) combination circuit

QWE4562009

(Transistor + MOS) & (MOS + MOS) combination circuit [Copy link]

(Transistor + MOS) & (MOS + MOS) combination circuit

When conducting, transistor + MOS consumes more power than MOS + MOS combination? Why? But it is more reliable! I found that direct use of microcontroller to drive MOS has caused insufficient conduction! Which method do you think is better? From what angles can it be analyzed?

蓝雨夜

I think the current required for transistor operation is larger than that of MOS.

QWE4562009

Blue Rainy Night posted on 2021-8-9 16:15 I think the current required for the transistor to work is greater than that of MOS,

That's for sure. It's the current type.

lcofjp

The two circuits are different, there is no comparison.

annysky2012

I always think it depends on the needs. Each has its own advantages, and the effects will be different when used in different places. It cannot be generalized.

se7ens

You don't connect resistors between Q2 and Q4 to limit the current.

Want to burn the tube?

In addition, BJT definitely consumes more power than MOSFET.

The reason why the MOS+MOS combination cannot be turned off is that you added diode D9 to the MCU control end. Removing it can turn off the MOS.

QWE4562009

se7ens posted on 2021-8-10 14:24 Do you want to burn the tube by not connecting a resistor between Q2 and Q4 to limit the current? In addition, BJT definitely has a larger current than MOSFET and consumes more power than MOS+MOS combination switch...

Q2 conduction does not require a current limiting resistor