Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

High Side Mosfet Driver

Status
Not open for further replies.

Muhammad Owais

New Member
i configure the high side mosfet driver circuit but its not work. the gate voltage is not enough to operate the mosfet.if any mistake in this circuit... please guide me
 

Attachments

  • IR2110 - 4.png
    IR2110 - 4.png
    30.1 KB · Views: 608

ronsimpson

Well-Known Member
Most Helpful Member
Search this forum for posts on high side drivers, IR2110, etc. This is a common problem.
1) the MOSFET can not be on 100 % of the time! 90% is max.
2) must be on/off/on/off to the input of the IR2110.
3) There must be a load on the MOSFET! Something must pull the output down hard when the MOSFET is off.
 

Flyback

Well-Known Member
your c1 looks too big.........remember you really need a diff probe to view the high side voltage properly.
 

tomizett

Active Member
R3 look like your problem - there's no need for a resistor there. All it's doing is discharging C1/C2 while the MOSFET is turned on and, given that C1 is so large, it's probably not having time to charge up again during the off period.
I agree with Flyback - I don't think C1 needs to be anything like that big. 1u should be plenty, 100n should even be fine.

Everything that Ronsimpson says is good advice too, especially the (not-so-obvious) point about needing to pull the output down when the MOSFET is off.
 

Flyback

Well-Known Member
I agree about the 1k, but you often need to dampen oscillation in high side drives.....maybe you should get rid the 1k but put a protection zener there, and a protection diode too...both in shunt.
 

tomizett

Active Member
Good point.
The "gate stopper" R1 is intended to dampen oscillation by slowing the turn-on, but you may need to experiment with its value (maybe start with D3 removed from circuit too?).
A zener (say 12-18v) connected in place of R3 will act to clamp the gate-source voltage and prevent damage to the MOSFET.
 

ronsimpson

Well-Known Member
Most Helpful Member
Most people don't understand how he high side driver works.
C1,2 is a little battery that powers a amplifiers that drives the MOSFET's gate. (and unfortunately R3)
OUT must be at or near ground for a while so power can flow through D1 into C1,2 (charging them). The return path to ground is through OUT. (must be at ground for a while)
When MOSFET is on then C1,2 is sitting above 300 volts and there is nothing to charge C1,2. As long as there is a charge in your battery the MOSFET can be on. Long before the energy is discharged (into R3) the MOSFET must be turned off for a while so that you battery (C1,2) can be recharged.

I agree with all, R3 should not be 1k. Maybe 100k. Maybe no resistor.

It is common on the forum for some one to say "IR2110 not working" when they are trying to get the MOSFET to be on 100% of the time.
 

Flyback

Well-Known Member
good points of course, ..I was assuming that the ir2110 here is being used in say a bridge smps...but of course, it may well not be intended for that.
Does IR2110 have UV shutdown, because that 22uf might linger too long at low voltage at start up and result in the fet not being fully enhanced....again, I am assuming smps style operation.......as pointed out, the caps get repeatedly charge pumped...or at least, they should do.
 

Muhammad Owais

New Member
if all of you are saying.........C1 (22uf) is too large so what value you suggest me to replace it.................and also the value of R3 (1k) i read on a forum that if there is no gate-to-sorce resistor .....mosfet will burn...??
 

Flyback

Well-Known Member
you can work cap out from Q=CV and I=c.dv/dt
Also the gate charge parameter of the mosfet and the switching frequency.
Keep the resistor , but use the v(t)=Vexp(-t/rc) EQUATION TO SEE HOWMUCH IT WILL DISCHARGE THE CAP (sorry about capitals).
MOsfet will burn?...check to see if it (ir2110) actively drives to common.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Top