CM6565 Datasheet, PDF (12/19 Pages) Champion Microelectronic Corp. – Noise Free 16 pin Self-Start Interleaved PFC with 180 Degree Phase Shift CRM PFC Controller for 90+/85+

CM6565
Noise Free 16 pin Self-Start Interleaved PFC with
180 Degree Phase Shift CRM PFC Controller for 90+/85+
Vrms1 (PIN 4) and Vrms2 (PIN 5)
Vrms1 and Vrms2: These two pins will represent the rms value of the line input voltage information without using additional high
voltage resistors. Vrms1 will take the IAC current + RC filters to obtain the voltage level with the first pole and the first pole
frequency is about 12Hz. The second RC pole level at about 5 Hz is the Vrms2 level. Vrms1 takes this voltage information to
determine the AC Brown Out Level. When Vrms1 is above 3V, both PFCout(master) and PFCout(slave) start with Veao Soft Start.
When Vrms1 is below 2V, both Veao and SS are pulled down.
Vrms2 also is the input of Gain Modulator which provides the about constant power limit. The average value of 2 x Vrms2 needs
to equal to the average value of the Vrms1.
VFB (PIN 15)
VFB also serves several functions:
1. Transconductance Amplifier speed up the load transient and the line transient.
2. VFB PIN is the inverting input of Transconductance Amp, GM.
3. Fast and Precision PFC Over Voltage Protection
4. CM6565 is implemented with GM; therefore, it does not require a local feedback (Which is a must item for the Conventional
Operational Amplifier.) Its compensation network is connected between VEAO and GROUND and there is not feedback
compensation network between VEAO and VFB.
5. Since there is no local feedback between VEAO and VFB, the VFB node can sense the PFC output voltage without any
delay; not like the conventional operational amplifier (It has 100mS time constant. This may stress the 380V PFC output
capacitor.) CM6565’s PFCOVP use the VFB pin to sense the PFC over voltage condition without any delay.
6. Comply with UL1950, single fault protection without any additional external circuit. At VFB pin, CM6565 has been
implemented with the tri-fault protection circuit to ensure the system power supply can comply with the UL1950.
VEAO (PIN 16)
VEAO is the output pin of GM. It can be used as the conventional OP but we not suggest because it will dramatically slow down
the system speed. For the proper usage of the VEAO, the compensation network should be connected between VEAO and
GROUND.
VEAO pin also is the input pin of the low-power-detect comparator. When VEAO potential goes low, it means the power supply
system needs less power. When VEAO potential goes high, it means the power supply system needs more power. VEAO
potential represents the power status of the power supply. CM6565 uses the VEAO potential to determine if the power supply is
at either the light load or the heavy load.
ZCDmaster (PIN 2)
The master PFC will determine when the slave PFC to turn on. The ZCDmaster sense the demagnetized winding signal from the
master PFC boost inductor and its threshold is 80mV. It does not require a diode to rectify the signal. ZCDmaster is clamped
between -0.7V to +0.7V by two back-to-back diodes to ground. Do not sink or source more than 100uA. An RC filter may be
needed to obtain the best ZVS performance while ZCS is sure thing.
Layout notice : the resister of connect the inductor and IC must be close to IC (pin2).
2008/10/09 Rev1.0
Champion Microelectronic Corporation
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