Dose L6562‘s inv pin has the same “disable function�? as l6562a？

RLiu.5 · ‎2021-11-24

Hello,

I compared the datasheet of L6562 and L6562A. Section 7.2 of L6562A mentioned that inv pin has dual functions and can be used as disable function. Is there the same function in L6562?

If not, what way should L6599A use the switch to control L6562? (I saw in L6599A that L6599A can control L6562, mentioned in Figure21).

Thank you

Peter BENSCH · ‎2021-11-25

Welcome, @RLiu.5, to the community!

No, unfortunately the L6562 does not yet have this disable function, it was only added in the successor L6562A.

The L6599A has a special pin with which the upstream PFC can be switched off: PFC_STOP. The datasheet of the L6599A says:

To help the designer meet energy saving requirements even in power-factor-corrected systems, where a PFC pre-regulator precedes the DC-DC converter, the L6599A allows that the PFC pre-regulator can be turned off during burst mode operation, therefore eliminating the no load consumption of this stage (0.5...1W). There is no compliance issue in that, because EMC regulations on low-frequency harmonic emissions refer to nominal load, no limit is envisaged when the converter operates with light or no load.

To do so, the L6599A provides pin 9 (PFC_STOP): it is an open collector output, normally open, that is asserted low when the IC is idle during burst mode operation. This signal is externally used for switching off the PFC controller and the pre-regulator, as shown in Figure 26.

For examples of how PFC_STOP disables the PFC, see the application notes on the L6599A website.

Good luck!

If the problem is resolved, please mark this topic as answered by selecting Select as best. This will help other users find that answer faster.

/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

View solution in original post

Peter BENSCH · ‎2021-11-25

Welcome, @RLiu.5, to the community!

No, unfortunately the L6562 does not yet have this disable function, it was only added in the successor L6562A.

The L6599A has a special pin with which the upstream PFC can be switched off: PFC_STOP. The datasheet of the L6599A says:

To help the designer meet energy saving requirements even in power-factor-corrected systems, where a PFC pre-regulator precedes the DC-DC converter, the L6599A allows that the PFC pre-regulator can be turned off during burst mode operation, therefore eliminating the no load consumption of this stage (0.5...1W). There is no compliance issue in that, because EMC regulations on low-frequency harmonic emissions refer to nominal load, no limit is envisaged when the converter operates with light or no load.

To do so, the L6599A provides pin 9 (PFC_STOP): it is an open collector output, normally open, that is asserted low when the IC is idle during burst mode operation. This signal is externally used for switching off the PFC controller and the pre-regulator, as shown in Figure 26.

For examples of how PFC_STOP disables the PFC, see the application notes on the L6599A website.

Good luck!

If the problem is resolved, please mark this topic as answered by selecting Select as best. This will help other users find that answer faster.

/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

RLiu.5 · ‎2021-11-29

Dear peter

Thank you for answering my question.

I checked the L6599A website. The applications inside are all L6599A+L6563H, L6599A+L6564. Both solutions are PFC chips has dedicated PFC_OK pins to realize L6599A stopping PFC, which L6562 hasn't. Does L6599A unable to shutdown L6562？

/RLiu.5

Peter BENSCH · ‎2021-11-29

Correct, I am not aware of any way that the L6599A can shut down the L6562.

If the problem is resolved, please mark this topic as answered by selecting Select as best. This will help other users find that answer faster.

/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.