Diodes AP8801 - Manual

AP8801
500mA LED STEP-DOWN CONVERTER
AP8801
Document number: DS31765 Rev. 7 - 2
1 of 14
www.diodes.com
June 2012
© Diodes Incorporated
Description
The AP8801 is a step-down DC/DC converter designed to drive LEDs with
a constant current. The device can drive up to thirteen LEDs, depending on
the forward voltage of the LEDs, in series from a voltage source of 8V to
48V. Series connection of the LEDs provides identical LED currents
resulting in uniform brightness and eliminating the need for ballast
resistors. The AP8801 switches at frequency up to 700kHz. This allows
the use of small size external components, hence minimizing the PCB area
needed.
Maximum output current of AP8801 is set via an external resistor
connected between the V
IN
and SET input pins. Dimming is achieved by
applying either a DC voltage or a PWM signal at the CTRL input pin. An
input voltage of 0.2V or lower at CTRL shuts down the output at SW and
puts the device into a low-current standby state.
Features
• LED driving current up to 500mA
• Operating input voltage up to 48V
• High efficiency up to 92%
• High switching frequency up to 700kHz
• PWM/DC input for dimming control
• Built-in output open-circuit protection
• SO-8 and MSOP-8 are in “Green” Molding Compound (No Br, Sb)
ƒ Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
ƒ Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
1
2
3
4 5
6
7
8
(Top View)
NC SW
CTRL SET
SW V
IN
GND GND
AP8801
SO-8
1
2
3
4 5
6
7
8
(Top View)
NC SW
CTRL SET
SW V
IN
GND GND
AP8801
MSOP-8
Applications
• Commercial & industrial lighting
• Small LCD panel backlight
•
Appliances interior lighting
•
Architecture Detail lighting
Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl)
and <1000ppm antimony compounds.
Typical Application Circuit