BP3102 datasheet(8/10 Pages) BPS

8 / 10 page

BP3102

High Precision PSR Constant Current LED Driver

BP3102_DS_Rev.1.0

www.bpsemi.com

Bright Power Semiconductor Co. Confidential – Customer Use Only

OUT

P_PK

Where,

NP: primary winding turns of transformer

NS: secondary winding turns of transformer

IP_PK: peak current in MOSFET

Feedback Network

The BP3102 senses the output information through

the feedback network and the FB threshold voltage is

set to 1V. The ratio of FB upper resistor to lower

resistor is recommended to about 4.0. The FB upper

resistor can be set to 300KΩ~750KΩ to improve

efficiency of convertor.

The upper resistor on FB is also used for line

compensation.

The ratio of line compensation can be calculated by

the equation:

()

FBH

AUX

−

Where, RFBH is the upper resistor of the feedback

network.

Operation Switching Frequency

The BP3102 is designed to work in discontinuous

conduction mode and no external loop compensation

component is required while maintaining stability.

The maximum duty cycle is limited to 42%. The

maximum switching frequency should be set to less

than 100KHz and the minimum switching frequency

should be set to more than 20KHz. The maximum

and minimum switching frequency is limited in

BP3102 to ensure the stability of system.

The switching frequency can be set by the formula:

LED

Where, LP is the primary winding inductance of

transformer.

Protection Function

The BP3102 has several protection functions. The

internal MOSFET will be shut down immediately

when the voltage on VCC reaches the threshold of

OVP and the device will not recover until the

protection condition is removed. A 19V zener diode

is designed in the BP3102 to prevent the chip

damage from the abnormal situation.

The thermal shutdown circuitry in the BP3102

senses the die temperature after start up, and the

thermal protection threshold is set to 150℃ with a

hysteresi

℃

s. When the temperature on die of

BP3102 rises and reaches the threshold, the power

MOSFET will be shut down immediately and

maintained switch off until the temperature on die

falls 20 ℃ from thermal protection trigger point.

The system will work in low consumption mode

when the output LED short circuit or open circuit is

detected, while the BP3102 continuous to detect

output status until the LED recover to normal

condition, and then the device will be operate in

normal mode.

PCB Layout

The following rules should be followed in BP3102

PCB layout:

Bypass Capacitor

The bypass capacitor on VCC should be as close as

possible to the VCC pin

Ground Path

The power ground path for current sense should be

short, and the power ground path should be separated

from small signal ground path before the negative of

the bulk capacitor.

The Area of Power Loop

The area of main current loop should be as small as

possible to reduce EMI radiation, such as the

primary current loop, the snubber circuit and the

secondary rectifying loop.

BP3102 데이터시트(PDF) 8 Page - Bright Power Semiconductor Co., Ltd.

BP3102 데이터시트(HTML) 8 Page - Bright Power Semiconductor Co., Ltd.

Html Pages

1 2 3 4 5 6 7 8 9 10

데이터시트 다운로드

링크 URL