BP3309 datasheet(6/8 Pages) BPS

6 / 8 page

BP3309

PSR Single-Stage APFC Offline LED Controller

BP3309_DS_Rev 1.2

www.bpsemi.com

Bright Power Semiconductor Co. Confidential – Customer Use Only

Internal Block Diagram

Demag

&OVP

VREF

Start

UVLO

&VREF

Current

Sense

Current

Control

Logic

Protection

Driver

PFC

Control

OUT

VCC

COMP

GND

Figure 3. BP3309 Internal Block Diagram

Function Description

The BP3309 is a high precision PSR single-stage

Active PFC controller for offline constant current

LED lighting. By using critical conduction mode, the

controller achieves high power factor, low THD and

high efficiency.

Start Up

The capacitor at ST pin is charged from the rectified

bus voltage through the start-up resistor when the

system

powered

(the

capacitor

recommended to 470nF), and VCC voltage will

follow ST pin voltage ramp (the VCC capacitor is

recommended to 2.2uF). The BP3309 uses source

driver architecture and patent pending internal

charging circuit for ultra fast VCC startup, while need

not compromise the system efficiency.

Once the voltage on VCC reaches the start-up

threshold, the BP3309 starts to switch and the

internal charging circuit turns off. Then the VCC is

supplied by the auxiliary winding. At the first

switching cycles, the switching frequency is 7kHz

and the LED current is softly rising up to avoid

overshoot. The total time from power on to LED turn

on is around 200ms @85Vac, even with 1MΩ startup

resistor.

At normal operation, in case the LED number is very

few and the auxiliary winding can’t supply the V

CC,

the internal charging circuit will turn on again to

supply the VCC. Then VCC will stay at a voltage near

10V, and the system still can work normally. With

this function, the system can work at wide range of

LED numbers.

Constant Current Control

The BP3309 uses proprietary current sensing scheme,

it can precisely control the LED current without

secondary side sense and feedback circuit including

opto-coupler.

BP3309 датащи(PDF) 6 Page - Bright Power Semiconductor Co., Ltd.

BP3309 датащи(HTML) 6 Page - Bright Power Semiconductor Co., Ltd.

Html Pages

1 2 3 4 5 6 7 8

датащи скачать

ссылки URL