On-chip Low power PWM or PFM

[Mohammad Ibrahim]

Need a low power PWM or PFM MOSFET circuit for controlling transitor in boost converter.
Or do you have Any idea to generate a square clock from sine wave?

 

[KlausST]

Hi,

No electrical specifications?
Frequency range voltage levels, duty cycle range...

Especially when you require "low power" ... then you need to give a useful value for this.
Noboby can guess what "low power" means for you..
"As low as possible" is no valid specification.

Klaus

 

[crutschow]

Any idea to generate a square clock from sine wave?

You can use a comparator, such as the LM339/393.
What is generating the sinewave?

 

[dick_freebird]

Choice of PFM vs PWM must consider the other content / function of the chip or board. RF in particular does not like PFM for its variable fundamental frequency (and harmonics). Although PFM in a well tuned resonant scheme can exude less RF energy to begin with, you can't define a frequency plan around "whatever".

 

[BradtheRad]

2-transistor boost converter (modified from version seen on internet).
PNP & NPN arranged as a sziklai pair, producing 'snap action' which is necessary to switch coil On and Off.
Boosts 1V to flash a 3.6V bright white led.