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13

STBY

Standby function. This pin is a high-impedance one as long as the voltage on pin COMP is

higher than 3V. When the voltage on pin COMP falls below 3V, the voltage on the pin tracks

that on pin COMP and is capable of sinking current. A resistor connected from the pin to the

oscillator allows programming frequency foldback at light load.

14

PFC_STOP

Open-drain ON/OFF control of PFC controller. This pin is intended for driving the base of a

PNP transistor in systems comprising a PFC pre-regulator, to stop the PFC controller at

light load by cutting its supply. The pin, normally low, opens if the voltage on COMP is lower

than 2.2V and goes back low when the voltage on pin COMP exceeds 2.7V. Whenever the

IC is shutdown, either latched (DIS >2.2V, ISEN >1.5V) or not (UVLO, SKIPADJ<0.8), the

pin is open as well.

15

S-COMP

Voltage ramp for slope compensation. When the gate-drive output is high the pin delivers a

is low the voltage delivered is zero. The pin is to be connected to pin ISEN via a resistor to

make slope compensation and allow stable operation at duty cycles close to and greater

than 50%.

16

RCT

Oscillator pin. A resistor to VREF and a capacitor to GND define the oscillator frequency (at

full load). A resistor connect to STBY modifies the oscillator frequency when the voltage on

pin COMP is lower than 3V.

Table 5. Electrical Characteristcs

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

SUPPLY VOLTAGE

Vcc

Operating range

After turn-on

9.4

22

V

Turn-on threshold

(1)

12.5

13.5

14.5

V

Turn-off threshold

8.0

8.7

9.4

V

Hys

Hysteresis

4.0

V

Zener Voltage

Icc = 20 mA

22

24

28

V

SUPPLY CURRENT

Start-up Current

Before turn-on,

150

µA

Quiescent Current

After turn-on

2

2.5

mA

Operating Supply Current

4

mA

Shutdown quiescent

current

180

µA

1

1.8

mA

1.3

mA

HIGH-VOLTAGE START-UP GENERATOR

Breakdown voltage

700

V

Start voltage

60

80

105

V

Vcc charge current

0.55

0.85

1

mA

ON-state current

1.6

mA

0.8

Leakage current (OFF state)

40

µA

HV generator restart voltage

4.4

5

5.6

V

12

13

14

V

Table 4. Pin Description (continued)

Pin

Number

Pin Name

Function