MC33363BDW Ver la hoja de datos (PDF) - ON Semiconductor

Número de pieza

componentes Descripción

Fabricante

MC33363BDW

High Voltage Switching Regulator

ON Semiconductor 

MC33363B

Pin

1

2

3

4, 5, 12, 13

6

7

8

9

10

11

14, 15

16

Function

Startup Input

−

VCC

Ground

RT

CT

Regulator Output

Compensation

Voltage

Feedback Input

Overvoltage

Protection Input

−

Power Switch

Drain

PIN FUNCTION DESCRIPTION

Description

This pin connects directly to the rectified ac line voltage source. Internally Pin 1 is tied to the drain of

a high voltage startup MOSFET. During startup, the MOSFET supplies internal bias, and charges an

external capacitor that connects from the VCC pin to ground.

This pin has been omitted for increased spacing between the rectified ac line voltage on Pin 1 and

the VCC potential on Pin 3.

This is the positive supply voltage input. During startup, power is supplied to this input from Pin 1.

When VCC reaches the UVLO upper threshold, the startup MOSFET turns off and power is supplied

from an auxiliary transformer winding.

These pins are the control circuit grounds. They are part of the IC lead frame and provide a thermal

path from the die to the printed circuit board.

Resistor RT connects from this pin to ground. The value selected will program the Current Limit

Comparator threshold and affect the Oscillator frequency.

Capacitor CT connects from this pin to ground. The value selected, in conjunction with resistor RT,

programs the Oscillator frequency.

This 6.5 V output is available for biasing external circuitry. It requires an external bypass capacitor of

at least 1.0 mF for stability.

This pin is the Error Amplifier output and is made available for loop compensation. It can be used as

an input to directly control the PWM Comparator.

This is the inverting input of the Error Amplifier. It has a 2.6 V threshold and normally connects

through a resistor divider to the converter output, or to a voltage that represents the converter output.

This input provides runaway output voltage protection due to an external component or connection

failure in the control loop feedback signal path. It has a 2.6 V threshold and normally connects

through a resistor divider to the converter output, or to a voltage that represents the converter output.

These pins have been omitted for increased spacing between the high voltages present on the

Power Switch Drain, and the ground potential on Pins 12 and 13.

This pin is designed to directly drive the converter transformer and is capable of switching a

maximum of 700 V and 1.0 A.

Capacitor CT

Compensation

Oscillator Output

PWM

Comparator

Output

PWM Latch

Q Output

Power Switch

Gate Drive

Leading Edge

Blanking Input

(Power Switch

Drain Current)

2.6 V

0.6 V

Normal PWM Operating Range

Output Overload

Figure 18. Timing Diagram of Normal Operation

http://onsemi.com

7

Current Limit

Propagation

Delay

Current

Limit

Threshold

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