L6564 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'L6564' PDF : 34 Pages View PDF
L6564
3
Pin connection
Pin connection
Figure 2. Pin connection
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Table 3. Pin description
n° Name
Function
Inverting input of the error amplifier. The information on the output voltage of the PFC pre-
1
INV
regulator is fed into the pin through a resistor divider.
The pin normally features high impedance.
Output of the error amplifier. A compensation network is placed between this pin and INV (pin
1) to achieve stability of the voltage control loop and ensure high power factor and low THD.
2
COMP
To avoid uncontrolled rise of the output voltage at zero load, when the voltage on the pin falls
below 2.4 V the gate driver output will be inhibited (burst-mode operation).
Main input to the multiplier. This pin is connected to the rectified mains voltage via a resistor
3
MULT divider and provides the sinusoidal reference to the current loop. The voltage on this pin is used
also to derive the information on the RMS mains voltage.
Input to the PWM comparator. The current flowing in the MOSFET is sensed through a resistor,
the resulting voltage is applied to this pin and compared with an internal reference to determine
MOSFET’s turn-off.
4
CS
A second comparison level at 1.7V detects abnormal currents (e.g. due to boost inductor
saturation) and, on this occurrence, activates a safety procedure that temporarily stops the
converter and limits the stress of the power components.
Second input to the multiplier for 1/V2 function. A capacitor and a parallel resistor must be
connected from the pin to GND. They complete the internal peak-holding circuit that derives the
information on the RMS mains voltage. The voltage at this pin, a dc level equal to the peak
voltage on pin MULT (3), compensates the control loop gain dependence on the mains voltage.
5
VFF
Never connect the pin directly to GND but with a resistor ranging from 100K ohm (minimum) to
2M ohm (maximum). This pin is internally connected to a comparator in order to provide the
brownout (AC mains undervoltage) protection. A voltage below 0.8V shuts down (not latched)
the IC and brings its consumption to a considerably lower level. The IC restarts as the voltage
at the pin goes above 0.88V.
Doc ID 16202 Rev 1
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