HI! I have a L4960 switching regulator, I want to know if there is a formula to calculate the switching frequency in fuction of the resistor and capacitor connected to pin 5. Also if you know more information about the pin 3 and pin 6 functionalitys it will be very helpful.
Thank you.
Welcome, @Community member, to the community!
First of all, the L4960 is already discontinued and unfortunately there is no support for it anymore.
Nevertheless, I will try to help you a little further because I had to deal with this many years ago. There is no formula for the switching frequency, but the data sheet contained a resistance vs. frequency diagram for different capacitor values. As far as I remember, you could set a switching frequency between 600...10kHz with 1.5nF and a resistor between 1...68kOhm, both connected in parallel and to GND.
Pin 3 was the frequency compensation pin for the control loop, typically 15kohms + 33nF in series to GND.
Pin 6 is connected to a capacitor for soft start, typically 2.2µF to GND, which is charged linearly by the pin 6 source current of about 140µA. This capacitor also influences the short-circuit current, but no more detailed information is available on this.
Does it answer your question?
Regards
/Peter
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