ACT6311 查看數據表（PDF） - Active-Semi, Inc

零件编号

产品描述 (功能)

生产厂家

ACT6311

White LED/OLED Step-Up Converter

Active-Semi, Inc 

ACT6311

Rev 4, 15-Nov-12

LOGIC

LED1

ACT6311

FB

R2

LED2

LED3

R1

Figure 4. Current Setting for White LED Application

LED1

LED2

ACT6311

FB

LED3

R3

R2

VDC

33.4k

56k

R1

62Ω

Figure 5. DC Voltage Controlled Dimming

R4

PWM

10k

LED1

LED2

ACT6311

FB

LED3

R3

R2

33.4k

56k

C1

R1

0.1µF

62Ω

Figure 7. Logic Controlled Dimming

Start-up and Inrush Current

In order to facilitate quick startup, a soft-start circuit

is not incorporated into the ACT6311. When the IC

is first turned on with no external soft-start circuit,

the peak inrush current is about 400mA. Figure 8

shows an implementation for soft-start. When

soft-start and dimming controls are used

simultaneously, a low frequency PWM signal (less

than 10kHz) or the methods in Figures 5, 6 and 7

should be used.

Open-Circuit Protection (White LEDs)

If one of the LEDs is disconnected, the FB voltage

drops to zero and the IC switches at maximum duty

cycle. This results in a high voltage that may

exceed the SW voltage rating. To limit this voltage,

use a Zener diode as shown in Figure 9. The Zener

voltage must be large than the total forward voltage

of the LEDs and the current rating should be higher

than 0.1mA.

Board Layout

To reduce EMI, minimize the area and path length

of all traces connected to SW. Use a ground plane

under the switching regulator and connect R1

directly to the G pin of the IC.

Figure 6. Filtered PWM Controlled Dimming

Innovative PowerTM

-6-

www.active-semi.com

Copyright © 2012 Active-Semi, Inc.

Share Link: