al8805 Diodes, Inc., al8805 Datasheet - Page 13

• Manufacturer Part Number: al8805
• Description: High Efficiency 30v 1a Buck Led Driver
• Manufacturer: Diodes, Inc.

Applications Information
Application Example
Typical application example for the AL8805 is the
MR16 lamp. They typically operate from 12V
using
electronic transformers.
As a replacement in some halogen lamp applications LEDs
offer a more energy efficient solution – providing no radiated
heat and no Ultra Violet light.
This application example is intended to fit into the base
connector space of an MR16 style LED lamp. The design
has been optimized for part count and thermal performance
for a single 3W LED in the Lens section.
An inductor choice of 33µH with saturation current higher
than 1.1A, will limit the frequency variation between 230kHz
and 350kHz over the whole input voltage variation (8V to
18V), and therefore represent the best choice for an
MR16 solution also taking into account the size constraint of
the lamp.
AL8805
Document number: DS35030 Rev. 1 - 2
conventional
Figure 35. Recommended PCB Layout
Figure 36. MR16 Schematic
electromagnetic
AL8805
AL8805
(cont.)
transformers
DC
or 12V
www.diodes.com
AC
or
13 of 16
,
HIGH EFFICIENCY 30V 1A BUCK LED DRIVER
The AL8805 guarantee high level of performance both with
12V
The efficiency is generally higher than 81% and current
regulation is better than 0.1mA/V in for a DC input voltage in
the range from 8V to 18V.
In table 1 can be found the bill of material of the
MR16 application example.
In figures 37 and 38 are displayed the top layer and the
bottom layer of a typical PCB design for an MR16 solution.
AC
and 12V
DC
Figure 38. Bottom Layer
power supply.
Figure 37. Top Layer
AL8805
© Diodes Incorporated
September 2010