Frequency Manipulation on TOP264-271
I am working with a TOP264-271. The circuit is running fine. However, at this point, I would very much like to learn if there is some way to “trick” or force the part to switch at a given frequency rather than “chose” the frequency based on load. Right now, I have the frequency pin tied to the control pin as recommended in the datasheet. However, I would like to be able to manipulate the running frequency.
I believe this “frequency control” will turn out to be important enough that I MAY be willing to consider an alternative part from PI that could drop into the same “socket”. That is, it need not be pin/pin to the TOP264-271 being used now. Close enough to “dead-bug” so I can wire in should be OK, so long as it is close enough NOT end up as a real rats nest.
Please advise.
David DeLeonardo
Future Electronics FAE
Comments
Thank you PI-SevenofNine:
Can you please suggest an alternate device from Power Integrations that is designed to operate at fixed and adjustable frequency? I would like to use my existing board but I am certainly able to wire into an alternative pin out, NO problem at all.
Please advise.
David
Thank you PI-SevenofNine:
Can you please suggest an alternate device from Power Integrations that is designed to operate at fixed and adjustable frequency? I would like to use my existing board but I am certainly able to wire into an alternative pin out, NO problem at all.
Please advise.
David
Hi David,
Unfortunately we don't have any device that is frequency selectable. Most of our controllers are ON-OFF controller and the maximum frequency are set (i.e. 132kHz or 66kHz selectable). This frequencies only varies if you change the load depending on the output power needed. Thank you.
Best Regards,
PI-SevenofNine
Hi David,
Thank you for using and promoting PI product on your design. As you may know, there are 4 different control modes for this device. At maximum load the IC operates either 132kHz or 66kHz depending on where you connect the control PIN. This frequency is fix and internal to the IC. However if you reduced the load the IC will enter into variable frequency PWM mode. This may be the area you want to explore. Right now, we don't have any circuit yet to operate the IC only in this region, but you may try to check with external circuit on the control pin and forcing the IC to operate in variable frequency operation. Thank you.
Best Regards,
PI-SevenofNine