MP4690 – SMART BYPASS FOR LED OPEN PROTECTION

MP4690 Rev. 1.0

www.MonolithicPower.com

9

7/7/2011

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2011 MPS. All Rights Reserved.

Figure 5 PCB Layout

The high current path (LED1 Anode, U1 Drain,

U1 Source, LED1 Cathode) should be placed

very close to the device with short, direct and

wide trace. U1 should be placed as close as

possible to the protected LED.

LED Dimming

MP4690 also work well with various brightness

control methods for LEDs. The brightness of

LEDs is best controlled by pulse width

modulation (PWM) with the switching frequency

typically between 100Hz and 1kHz. Dimming

via DC current can cause unwanted color shifts.

Either way, MP4690 will not interfere with the

dimming strategy employed.