ZLED7002

Toggle (Side-Step) Dual-Channel LED Driver

Data Sheet

August 10, 2011

© 2011 Zentrum Mikroelektronik Dresden AG — Rev.3.0

All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without

the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.

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Figure 1.2

Main LED Current versus Power Supply (4V to 5.4V DC)

2

Circuit Description

2.1.

ZLED7002 Overview

The ZLED7002 is an LED driver for two channels designated as the MAIN channel and the SUB channel. Typically, only one

of the channels is on and the other is off. External resistors R1 and R2 connected to UV pin form a voltage divider across the

power supply. When the power supply voltage has risen high enough to create a voltage at the UV pin that is above a set

threshold, the MAIN LED channel is activated and the SUB channel is off. If the supply falls and the resulting voltage at the UV

pin is below the threshold, the SUB channel becomes active and the MAIN channel is turned off.

When the MAIN channel is active, the ZLED7002 provides a constant current source for driving the MAIN LED channel. Its

current level is set by an external resistor (R3) between the Iset and GND pins (see section 2.3). When the SUB LED channel

is active, its current is determined by external components (see section 2.4) and the ZLED7002 pulls the SUB pin to ground.

Refer to the application circuit in Figure 3.1 for the location of the components referred to in the following sections.