The IC in question is in the link here.
There may be a better IC to use but I don't know which.
I'm building a buck converter to reduce 14v to 6v. I'd like to use an 8-pin pwm IC and external mosfet to increase it's current. Is there a way to use pin-1 (collector) and bootstrap the output to drive an N-ch mosfet?
There may be a better IC to use but I don't know which.
I'm building a buck converter to reduce 14v to 6v. I'd like to use an 8-pin pwm IC and external mosfet to increase it's current. Is there a way to use pin-1 (collector) and bootstrap the output to drive an N-ch mosfet?
I don't think so as long as it can drive a mosfet gate. I need 6A of current from my converter so I'll likely need to use an external mosfet switch. I could go synchronous if I can find a compatible controller IC.
Here's the features I'd like.
-Synchronous operation
-Low voltage shutdown when VCC < ~10v
-Feedback input for voltage regulation
-Current limiting/regulation (optional)
-Programmable soft-start
-Some way to enable the controller with a low current signal. I can pull down the softstart capacitor if softstart input begins at >0.6v (so a pnp transistor can hold it low)
Here's the features I'd like.
-Synchronous operation
-Low voltage shutdown when VCC < ~10v
-Feedback input for voltage regulation
-Current limiting/regulation (optional)
-Programmable soft-start
-Some way to enable the controller with a low current signal. I can pull down the softstart capacitor if softstart input begins at >0.6v (so a pnp transistor can hold it low)
Last edited:
Isn't bootstrapping only needed to drive a high side mosfet where the output is higher than the drive voltage?
You don't need it here. 14V is more than enough to drive outputs in your case.
Why not use the IC you linked, with a external transistor, as per datasheet?
You don't need it here. 14V is more than enough to drive outputs in your case.
Why not use the IC you linked, with a external transistor, as per datasheet?
Source pin on the high side mosfet will be whatever Vcc is when it's turned on. Input ranges from 10-14v.
The IC shows a transistor. I'd like to use a mosfet for efficiency sake. Even the integrated buck controllers (power device and control circuitry in one package) use a bootstrap cap if the controller contains a mosfet switch.
There are both controllers and 1 chip solutions. I use tps54427, but its only up to 4 A. Search at digikey or any other distributor!
I used mc34063 as a buck with upper pFET, but I dont recommend.
I used mc34063 as a buck with upper pFET, but I dont recommend.
That's the same chip in the first link. I need to bootstrap that if I want to drive an nch fet as an external switch.
Is it possible to make a voltage regulated boost converter out of this IC? http://www.irf.com/product-info/datasheets/data/irs25401pbf.pdf
Buck non-synchronous n-type switch
Website specifically showing how to bootstrap a MOSFET with the exact IC you are trying to use.
Website specifically showing how to bootstrap a MOSFET with the exact IC you are trying to use.
- Status
- Not open for further replies.