RT8511B

2

DS8511B-05

February 2015

www.richtek.com

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Copyright

2015 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Pin No.

Pin Name

Pin Function

1

OVP

Over Voltage Protection for Boost Converter. The detecting threshold is 1.2V.

2

FB

Feedback. Connect a resistor between this pin and GND to set the LED current.

3

DIMC

PWM Filter. Filter the PWM signal to a DC voltage.

4

GND

Ground.

5

LX

Switch Node for Boost Converter.

6

VIN

Power Supply Input.

7

PWM

Dimming Control Input.

8

EN

Chip Enable (Active High) for Boost Converter.

9 (Exposed Pad)

GND

The exposed pad must be soldered to a large PCB and connected to AGND for

m aximum power dissipation.

Functional Pin Description

Typical Application Circuit

Figure 1. Typical Application Circuit of Normal Operation

Figure 2. Typical Application Circuit of Low Voltage Operation

RT8511B

L

FB

VIN

GND

OVP

LX

:

:

:

:

:

:

:

:

:

:

:

:

WLEDs

4.2V to 24V

EN

D

R2

R1

Chip Enable

1

4, 9 (Exposed Pad)

2

5

6

8

1µF x 2

3.3M

100k

10µH

1µF x 2

DIMC

3

1µF

PWM

7

PWM

100Hz to 8kHz

3.3

RT8511B

L

FB

VIN

GND

OVP

LX

:

:

:

:

:

:

:

:

:

:

:

:

WLEDs

2.7V to 24V

EN

D

R2

R1

Chip Enable

1

4, 9 (Exposed Pad)

2

5

6

8

1µF x 2

3.3M

100k

10µH

1µF

DIMC

3

1µF

PWM

7

PWM

100Hz to 8kHz

3.3

1µF x 2

2.7V to 4.2V