Diodes AP5724 User Manual
Ap5724, Description, Features
AP5724
Document number: DS31843 Rev. 4 - 2
1 of 15
December 2013
© Diodes Incorporated
AP5724
WHITE LED STEP-UP CONVERTER
Description
The AP5724 is a step-up DC/DC converter specifically designed to
drive white LEDs with a constant current. The device can drive 2 ~ 6
LEDs in series from a Li-Ion cell. Series connection of the LEDs
provides identical LED currents resulting in uniform brightness and
eliminates the need for ballast resistors. For driving higher number of
LEDs, AP5724 also supports a single feedback of parallel connected
multiple strings of equal number of LEDs.
The AP5724 switches at 1.2MHz that allows the use of tiny external
components. A low 0.1V feedback voltage minimizes power loss in
the current setting resistor for better efficiency
Features
•
High Efficiency: 84% Typical
•
Fast 1.2MHz Switching Frequency
•
Current Limit and UVLO Protections
• Internal
Thermal
Shutdown
•
Internal Over Voltage Protection
•
Integrated Soft-Start Function
•
SOT26, TSOT26 and U-DFN2020-6: Available in “Green”
Molding Compound (No Br, Sb)
•
Lead-Free Finish; RoHS Compliant (Notes 1 & 2)
Pin Assignments
1
2
3
74
6
OVP
FB
5
EN
SW
(Top View)
V
IN
GND
SOT26 / TSOT23-6
SW
V
IN
OVP
1
2
3
6
5
4
GND
FB
EN
(Top View)
U-DFN2020-6
Applications
• Cellular
Phones
•
PDAs, Hand held Computers
• Digital
Cameras
• MP3
Players
• GPS
Receivers
Notes:
1. EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. All applicable RoHS exemptions applied.
2. S more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
Typical Applications Circuit
V
IN
SW
EN
GND
FB
AP5724
C
OUT
1uF
R
SET
5
L1
22uH
D1
V
IN
C
IN
1uF
OVP
2~6 LEDs
PWM Dimming
OFF
ON
Figure 1 Typical Application Circuit
Pb