STMicroelectronics L6563H 100 W TM PFC demonstration board EVL6563H-100W EVL6563H-100W Ficha De Dados
Códigos do produto
EVL6563H-100W
Test results and significant waveforms
AN3063
24/33
Doc ID 16261 Rev 3
Figure 32.
EVL6563H on/off control by a cascaded converter controller via the
PFC_OK or RUN pin
PFC_OK or RUN pin
The third communication line is the PWM_STOP (pin #11), which works in conjunction with
the RUN (pin #12). The purpose of the PWM_STOP pin is to inhibit the PWM activity of both
the PFC stage and the cascaded DC-DC converter. The pin is an open collector, normally
open, that goes low if the device is disabled by a voltage lower than 0.8 V on the RUN (pin
#12). It is important to point out that this function works correctly in systems where the PFC
stage is the master and the cascaded DC-DC converter is the slave or, in other words,
where the PFC stage starts first, powers both controllers and enables/disables the operation
of the DC-DC stage. This function is quite flexible and can be used in different ways. In
systems comprising an auxiliary converter and a main converter (e.g. a desktop PC's silver
box or hi-end flatscreen TV or monitor), where the auxiliary converter also powers the
controllers of the main converter, the RUN (pin #12) can be used to start and stop the main
converter. In the simplest case, to enable/disable the PWM controller the PWM_STOP (pin
#11) can be connected to either the output of the error amplifier or, if the chip is provided
with it, to its soft-start pin.
the RUN (pin #12). The purpose of the PWM_STOP pin is to inhibit the PWM activity of both
the PFC stage and the cascaded DC-DC converter. The pin is an open collector, normally
open, that goes low if the device is disabled by a voltage lower than 0.8 V on the RUN (pin
#12). It is important to point out that this function works correctly in systems where the PFC
stage is the master and the cascaded DC-DC converter is the slave or, in other words,
where the PFC stage starts first, powers both controllers and enables/disables the operation
of the DC-DC stage. This function is quite flexible and can be used in different ways. In
systems comprising an auxiliary converter and a main converter (e.g. a desktop PC's silver
box or hi-end flatscreen TV or monitor), where the auxiliary converter also powers the
controllers of the main converter, the RUN (pin #12) can be used to start and stop the main
converter. In the simplest case, to enable/disable the PWM controller the PWM_STOP (pin
#11) can be connected to either the output of the error amplifier or, if the chip is provided
with it, to its soft-start pin.
The EVL6563H-100W offers the possibility to test these functions by connecting it to the
cascaded converter via the series resistors R28, R29, R30. Regarding the PWM_STOP (pin
#11) pin that is an open collector type, if it needs a pull-up resistor, please connect it close to
the cascaded PWM for better noise immunity.
cascaded converter via the series resistors R28, R29, R30. Regarding the PWM_STOP (pin
#11) pin that is an open collector type, if it needs a pull-up resistor, please connect it close to
the cascaded PWM for better noise immunity.
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Figure 33.
Interface circuits that let the
L6563H switch on or off a PWM
controller, not latched
L6563H switch on or off a PWM
controller, not latched
Figure 34.
Interface circuits that let the
L6563H switch on or off a PWM
controller, latched
L6563H switch on or off a PWM
controller, latched
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