ZSLS7025 Datasheet

© 2016 Integrated Device Technology, Inc.

11

April 20, 2016

(

)

FB

4

FB

DC

3

FB

OUT

R

R

V

V

R

V

I













−

×

−

=

2.6.1

Dimming Control Using an External DC Control Signal

The LED output current can be set below the nominal average value defined by equation (2) 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

causes the ZSLS7025 to compensate by reducing the output current through the LED string. Consequently, the

output current is inversely proportional to the DC control voltage.

applications.

The output current controlled by the DC voltage on FB can be calculated using equation (3).

(3)

Where

Figure 2.2

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

TOFF

GATE

ZSLS7025

LED

String

OVP

GND

VDD

ADJ

FB

CS