ZLED7010

40V LED Driver with Temperature Compensation

Data Sheet

August 12, 2010

© 2010 Zentrum Mikroelektronik Dresden AG — Rev. 1.1

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 PRELIMINARY and subject to changes

without notice.

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2

Circuit Description

proper LED current control. The ZLED7010 supports linear or PWM control of the LED current. It provides

temperature compensation to maintain stable and reliable operation of the LEDs. Only a few external

components are needed for typical applications.

2.1.

Voltage Supply

The ZLED7010 has an internal regulator that disables the LX output until the voltage supply rises above a

start-up threshold voltage set internally as needed to ensure that the power MOSFET on-resistance is low

enough for proper operation. When the supply voltage exceeds the threshold, the ZLED7010 begins normal

operation.

Important: The ZLED7010 must be operated within the operating voltage range specified in section 1.2 to

avoid conditions that could result in thermal damage to the ZLED7010. Operating with the supply voltage

below the minimum can result in a high switch duty cycle and excessive ZLED7010 power dissipation, risking

over-temperature conditions (also see section 4.1 regarding thermal restrictions) which could result in

activation of the ZLED7010’s thermal shut-down circuitry (see section 4.2). With multiple LEDs, the forward

drop is typically adequate to prevent the chip from switching below the minimum voltage supply specification

(6V), so there is less risk of thermal shut-down.

2.2.

ZLED7010 Standby Mode

drops to approximately 60μA. This standby mode minimizes current consumption.

2.3.

Output Current Control

The LED control current output on the LX pin is determined by the value of external components and the

external components are discussed in section 3. The subsequent sections describe the two options for control

† of 500kΩ ±25%.

2.3.1.

exceeding the maximum switch current (see section 1.3).

S

OUT

R

mV

95

I



(1)

Where