ZLED7000 Datasheet

© 2016 Integrated Device Technology, Inc.

17

April 20, 2016

7

Layout Requirements

7.1

Layout Considerations for ADJ (Pin 3)

For applications in which the ADJ pin is unconnected, minimize the length of circuit board traces connected to

ADJ to reduce noise coupling through this high impedance input.

7.2

Layout Considerations for LX (Pin 1)

Minimize the length of circuit board traces connected to the LX pin because it is a fast switching output.

7.3

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

The C1 input decoupling capacitor must be placed as close as possible to the VIN pin to minimize power supply

noise, which can reduce efficiency. See section 3.2 regarding capacitor selection.

7.4

Layout Considerations for GND (Pin 2)

The ZLED7000 GND (ground) pin must be soldered directly to the circuit board’s ground plane to minimize

ground bounce due to fast switching of the LX pin.

7.5

Layout Considerations for High Voltage Traces

Avoid laying out any high voltage traces near the ADJ pin to minimize the risk of leakage in cases of board

contamination, which could raise the ADJ pin voltage resulting in unintentional output current. Leakage current

can be minimized by laying out a ground ring around the ADJ pin.

7.6

Layout Considerations for the External Coil (L1)

The L1 coil must be placed as close as possible to the chip to minimize parasitic resistance and inductance,

which can reduce efficiency. The connection between the coil and the LX pin must be low resistance.

7.7

Layout Considerations for the External Current Sense Resistor (RS)

Any trace resistance in series with RS must be taken into consideration when selecting the value for RS.

8

Ordering Information

Product Sales Code

Description

Package

ZLED7000ZI1R

ZLED7000 – 40V LED Driver

SOT89-5 (Tape & Reel)

ZLED7000KIT-D1

ZLED7000 used in a MR16 Halogen replacement Demo

Kit 12VAC/VDC, including 1 ZLED-PCB1

Kit

ZLED-PCB1

Test PCB with one 3W white High Brightness (HB) LED,

cascadable to one multiple LED string

Printed Circuit Board (PCB)

ZLED-PCB2

10 unpopulated test PCBs for modular LED string with

footprints of 9 common HB LED types

Printed Circuit Board (PCB)