ZLED7000

40V LED Driver with Internal Switch

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 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

ZLED7000 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

5

ESD/Latch-Up-Protection ............................................................................................................................................ 16

6

Pin Configuration and Package................................................................................................................................... 17

7

Layout Requirements .................................................................................................................................................. 18

7.1

Layout Considerations for ADJ (Pin 3)................................................................................................................. 18

7.2

Layout Considerations for LX (Pin 1) ................................................................................................................... 18

7.3

Layout Considerations for VIN (Pin 5) and the External Decoupling Capacitor (C1)............................................. 18

7.4

Layout Considerations for GND (Pin 2)................................................................................................................ 18

7.5

Layout Considerations for High Voltage Traces................................................................................................... 18

7.6

Layout Considerations for the External Coil (L1) ................................................................................................. 18

7.7

Layout Considerations for the External Current Sense Resistor (RS) .................................................................. 18

8

Ordering Information ................................................................................................................................................... 18

9

Document Revision History ......................................................................................................................................... 19