Driver problem, please help!

我的眼里只有PCB

Driver problem, please help! [Copy link]

What driver chip is suitable for the MOS tube S3 in the topology below? Is TC4420 OK?

maychang

All three MOS tubes can use UCC27201. The advantage is that the types of chips are reduced. It seems that TC4420 is not necessary. The output current of TC4420 can reach 6A. I guess this model is more expensive.

我的眼里只有PCB

maychang posted on 2018-7-25 17:31 All three MOS tubes can use UCC27201. The advantage is that the types of chips are reduced. It seems that TC4420 is not necessary. The output current of TC4420 can reach 6A...

But, you just told me two days ago that the voltage between the source and ground of the switch tube S3 is constant, and no bootstrap chip is needed. It is best to use a high-speed optocoupler series.

maychang

All I see is PCB Published on 2018-7-25 19:51 But, you just told me two days ago that the voltage between the source and ground of the switch tube S3 is constant, and no bootstrap chip is needed. It is best to use a high-speed optocoupler series. :Cry ...

I didn't say "it is best to use a high-speed optocoupler series", I just said that high-speed optocouplers can be used. The advantage of using UCC27201 is that it reduces the number of chip types. Use UCC27201 without using its bootstrap function. The same is true for other types of high-speed optocouplers (these high-speed optocouplers do not have a bootstrap function).

我的眼里只有PCB

maychang posted on 2018-7-25 20:00 I didn't say "it's best to use high-speed optocoupler series", I just said that high-speed optocoupler can be used. The advantage of using UCC27201 is that it reduces the types of chips. Using UC ...

Well, OK, thank you!

maychang

I only have PCB in my eyes Published on 2018-7-25 21:16 Well, OK, thank you!

It seems that you have not figured out how the so-called "bootstrap" of this optocoupler isolation driver chip works. It is recommended to first understand the working process of "bootstrap", otherwise it will be difficult to choose the chip.

maychang

I only have eyes for PCB Published on 2018-7-25 21:16 Well, OK, thank you!

I don't know the price of UCC27201, it is probably quite expensive. In fact, all three MOS tubes can be driven by chips such as IR2101, of which S1S2 use bootstrap, while S3 cannot bootstrap, and can only add an isolated 12V power supply. IR2101 may be cheaper than UCC27201.