STMicroelectronics L6563H 100 W TM PFC demonstration board EVL6563H-100W EVL6563H-100W Data Sheet

Product codes
EVL6563H-100W
Page of 33
Main characteristics and circuit description
AN3063
4/33
Doc ID 16261 Rev 3
Main characteristics and circuit description
The main characteristics of the SMPS are listed below:
Line voltage range: 90 to 265 Vac
Minimum line frequency (f
L
): 47 Hz
Regulated output voltage: 400 V
Rated output power: 100 W
Maximum 2f
L
 output voltage ripple: 20 V pk-pk
Hold-up time: 10 ms (V
DROP
 after hold-up time: 300 V)
Minimum switching frequency: 40 kHz
Minimum estimated efficiency: 92% (at Vin = 90 Vac, Pout = 100 W)
Maximum ambient temperature: 50°C
PCB type and size: single side, 35 µm, CEM-1, 90 x 83 mm
This demonstration board implements a power factor correction (PFC) pre-regulator, 100 W 
continuous power, on a regulated 400 V rail from a wide-range mains voltage and provides 
for the reduction of the mains harmonics, allowing to meet the European EN61000-3-2 or 
the Japanese JEITA-MITI standard. The regulated output voltage is typically the input for the 
cascaded isolated DC-DC converter thatprovides the output rails required by the load. 
The board is designed to allow full-load operation in still air. 
The power stage of the PFC is a conventional boost converter, connected to the output of 
the rectifier bridge D1. It is completed by the coil L2, the diode D3 and the capacitor C6. The 
boost switch is represented by the power MOSFET Q1. The NTC R1 limits the inrush 
current at switch-on. It has been connected on the DC rail, in series to the output electrolytic 
capacitor, in order to improve the efficiency during low-line operation because the RMS 
current flowing into the output stage is lower than current flowing into the input one at the 
same input voltage, thus increasing efficiency. The board is equipped with an input EMI filter 
necessary to filter the commutation noise coming from the boost stage.
At startup the L6563H is powered by the electrolytic capacitor C11 that is charged via high-
voltage startup (HVS) pin #9. The HVS pin, able to withstand 700 V, is connected directly to 
the rectified mains voltage. A 0.85 mA (typ.) internal current source charges the capacitor 
C11 connected between Vcc pin #16 and GND pin #14 until the voltage on the Vcc pin 
reaches the startup threshold. The L2 secondary winding and the charge pump circuit (C7, 
R4, D4 and D5) generate the Vcc voltage, powering the L6563H during normal operation. 
The L2 secondary winding is also connected to the L6563H pin #13 (ZCD) through the 
resistor R5. Its purpose is to supply the information that L2 has demagnetized, needed by 
the internal logic for triggering a new switching cycle.
The divider R9, R12, R17 and R19 provides the L6563H multiplier with the information of the 
instantaneous mains voltage that is used to modulate the peak current of the boost.
The resistors R2, R8, R10 with R13 and R14 are dedicated to sense the output voltage and 
feed back to the L6563H the information necessary to regulate the output voltage. The 
components C9, R18 and C8 constitute the error amplifier compensation network necessary 
to keep the required loop stability.
The peak current is sensed by resistors R25 and R26 in series to the MOSFET and the 
signal is fed into pin #4 (CS) of the L6563H via the filter composed of R24 and C15.