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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Contents

1

IC Characteristics .......................................................................................................................................................... 6

1.1.

Absolute Maximum Ratings ................................................................................................................................... 6

1.2.

Operating Conditions ............................................................................................................................................. 6

1.3.

Electrical Parameters............................................................................................................................................. 6

1.4.

Characteristic Operating Curves............................................................................................................................ 8

2

Circuit Description ....................................................................................................................................................... 10

2.1.

Voltage Supply..................................................................................................................................................... 10

2.2.

ZLED7010 Standby Mode.................................................................................................................................... 10

2.3.

Output Current Control......................................................................................................................................... 10

2.3.1.

Output Current and RS.................................................................................................................................. 10

2.3.2.

PWM Control ................................................................................................................................................ 11

2.3.3.

External DC Voltage Control of Output Current ............................................................................................ 11

2.3.4.

Microcontroller LED Control.......................................................................................................................... 12

3

Application Circuit Design ........................................................................................................................................... 13

3.1.

External Component – Inductor L1 ...................................................................................................................... 13

3.2.

External Component – Capacitor C1 ................................................................................................................... 14

3.3.

External Component – Diode D1 ......................................................................................................................... 14

3.4.

Output Ripple....................................................................................................................................................... 15

4

Operating Conditions................................................................................................................................................... 16

4.1.

Thermal Conditions.............................................................................................................................................. 16

4.2.

Thermal Shut-Down Protection............................................................................................................................ 16

4.3.

Open-Circuit Protection........................................................................................................................................ 16

4.4.

External Temperature Compensation of Output Current...................................................................................... 16

5

Chaining Multiple ZLED7010 ICs ................................................................................................................................ 19

6

ESD/Latch-Up-Protection ............................................................................................................................................ 20

7

Pin Configuration and Package................................................................................................................................... 20

8

Layout Requirements .................................................................................................................................................. 22

8.1.

Layout Considerations for ADJI (Pin 6) ................................................................................................................ 22

8.2.

Layout Considerations for LX (Pin 8) ................................................................................................................... 22

8.3.

Layout Considerations for VIN (Pin 1) and the External Decoupling Capacitor (C1)............................................. 22

8.4.

Layout Considerations for GND (Pin 7)................................................................................................................ 22

8.5.

Layout Considerations for ADJO (Pin 5)............................................................................................................... 22

8.6.

Layout Considerations for RTH and RNTC (Pins 3 and 4)....................................................................................... 22

8.7.

Layout Considerations for High Voltage Traces................................................................................................... 22

8.8.

Layout Considerations for the External Coil (L1) ................................................................................................. 22

8.9.

Layout Considerations for the External Current Sense Resistor (RS) .................................................................. 22

9

Ordering Information ................................................................................................................................................... 23

10

Document Revision History ......................................................................................................................................... 23