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Document Number: 73861

S-70547–Rev. D, 26-Mar-07

Vishay Siliconix

SiP12506

OPEN-CIRCUIT PROTECTION:

In the event of an output open circuit (e.g. when the LEDs are

either disconnected form the output or an LED fails), the

feedback voltage will become zero causing the SiP12506 to

go to maximum duty cycle. This would generally result in a

high output voltage and, possibly, cause the voltage on the

LX pin to exceed it's absolute maximum rating and damage

the part. However, the SiP12506 has a built-in over-voltage

protection circuitry that will clamp the output to 20 V and guar-

antee safe operation under open-circuit conditions.

Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Tech-

nology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and reliability

Figure 11. White LED driver with adjustable brightness control using a filtered PWM signal

LX

FB

GND

SiP12506

4.7 µF

10 µH

1 µF

1

6

4

3

5

2

0.208 V

R1

R3

R2

0.1 µF

PWM > 22 KHz

R4

R5

R6

SHD

SHD

MBR0530

100 K

Ω

20 K

Ω

10 K

Ω

15

Ω

Figure 12. White LED driver with a fixed output and adjustable brightness control using a filtered PWM signal

LX

FB

GND

SiP12506

4.7 µF

10 µH

1 µF

1

6

4

3

5

2

0.208 V

R3

R2

R1

> 22 KHz

R4

R5

R6

PWM

MBR0530

SHD

SHD