ZLED7015 Datasheet

© 2016 Integrated Device Technology, Inc.

13

April 20, 2016

EN

LX

ZLED7015

LED

String

VIN = 6 to 30 VDC

COUT

R1

L1

CIN

D1

FB

PGND

AGND

OVP

R2

RS

VP

VDD

C1

CVDD

CVP

C2

RVDD

REN

COVP

R4

R3

DC Control Signal VDC = 0 to 5V

VOUT

EN

LX

ZLED7015

LED

String

VIN = 6 to 30 VDC

COUT

R1

L1

CIN

D1

FB

PGND

AGND

OVP

R2

RS

VP

VDD

C1

CVDD

CVP

C2

RVDD

REN

COVP

VOUT

Figure 2.1

Typical Application Circuit

2.2.2

Dimming via External DC Voltage Control

The LED output current can be set below the nominal average value defined on section 2.2.1 by using an external

DC voltage control signal superimposed on the FB pin as shown in the example circuit in Figure 2.2. As the DC

control signal, VDC, increases, the current through R3 increases with a subsequent increase in the voltage at the

FB pin. This causes the ZLED7015 to compensate by reducing the output current through the LED string.

Consequently, the output current is inversely proportional to the DC control voltage.

Note: It is important to ensure that the LED output voltage VOUT remains higher than the input voltage VIN in

dimming applications.

Figure 2.2

Example Circuit for Controlling Output Current via an External DC Control Voltage