ZLED7002 Datasheet

© 2016 Integrated Device Technology, Inc.

6

April 20, 2016

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.