Issues with TPS2811 MOSFET Driver for IRF530 in Buck SMPS Design

[pc9460]

Hi,

We give informations on partnumbers. Look at at least one of the datasheets found via the linear selection guide.

Please read it - or at least look at the pictures - then you will find out, that there is no need for external drivers nor external FETs. All inside.

As i wrote: 8 parts in total.
How can I say it more clearly? No need to generate a PWM. PWM controller with regulation loop inside. Constant 5V output voltage.

Klaus

The point me building this smps is that it has to be custom. I can't buy an ic that does the entire buck portion as it wouldn't be custom. Thanks for the input though!

 

[pc9460]

Any ideas for selecting an gate driver and would using a pwm controller ic work? Like will it keep the out of my buck converter 5v dc and adjust the duty cycle to keep it that consistent output.

 

[Easy peasy]

A PWM IC designed to drive a P fet, or a normal output one with some transistors to level shift the drive to a P fet will give you a working solution, better to keep the freq to 150-200kHz for efficiency and choice of buck inductors.
Even a low cost CMOS 555 timer can be configured to do this.

 

[pc9460]

Is there any ic on the market that will do the pwm with feedback capability? Like it will adjust the duty cycle of the pwm to keep the output at a constant 5v dc?

 

[BradtheRad]

To assist progress, here is a simulation which demonstrates how to drive a buck converter using hysteresis. An op amp is used as a comparator.

Apply 5.2V reference to one input. The output voltage is applied to the other input. (The current-sense resistor is not essential, however it makes for tighter regulation of output voltage.)



The op amp biases an NPN, which in turn biases a PNP. The op amp operates from a 5V supply (which can be provided by a zener diode and resistor combination).

The load can be changed, although it may require adjusting a few other values.