L5101

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

6 of 9

www.unisonic.com.tw

QW-R103-026,A

APPLICATION INFORMATION

Recommended Component Selection

Inductor Selection:

A 10µH inductor is recommended for most applications.

Capacitor Selection:

The small size of ceramic capacitors (1µF input with 1µF output ) are sufficient, X5R

and X7R types are recommended

Diode Selection:

An Schottky diode rated at 100mA ~ 200mA is sufficient for most applications.

LED Current Control

- Feedback reference voltage : 95mV.

VIN

SW

OVP

FB

GND

SHDN

L

10μH

C1

1μF

L5101

4.7Ω

C2

1μF

RB521S-30

D1

Fig.1 Dimming Control with a PWM Signal

Open-Circuit Protection

When a high output voltage exceeds maximum 33V, the built-in OVP (Over Voltage Protection) will be triggered to

prevent the damage resulting from an open circuit condition.

Dimming Control

There are three different ways of dimming control circuits as follows:

1. Using a PWM signal

SW

OVP

FB

GND

SHDN

C1

1μF

L5101

4.7Ω

RB521S-30

D1

PWM

R1

1KΩ

R2

51KΩ

L

10μH

Fig.2 Dimming Control Using a PWM Signal