NOT RECOMMENDED FOR NEW DESIGN USE AL8860 and AL8861 AP8800 350mA LED STEP-DOWN CONVERTER Description Pin Assignments The AP8800 is a step-down DC/DC converter designed to drive LEDs SO-8 with a constant current. The device can drive up to seven LEDs, depending on the forward voltage of the LEDs, in series from a ( Top View ) voltage source of 8V to 28V. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminates 1 SET CTRL 8 the need for ballast resistors. The AP8800 switches at frequency up 2 NC RSVD 7 to 0.6MHz. This allows the use of small size external components, AP8800 SW 3 NC 6 hence minimizing the PCB area needed. 4 5 GND V IN Maximum output current of AP8800 is set via an external resistor connected between the V and SET input pins. Dimming is achieved IN by applying either a DC voltage or a PWM signal at the CTRL input MSOP-8 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. ( Top View ) 1 CTRL 8 SET Features RSVD 2 7 NC LED Driving Current up to 350mA AP8800 SW 3 6 NC Compatible with 12V & 24V Standard Systems GND 4 5 V High Efficiency up to 92% IN High Switching Frequency up to 0.6MHz PWM/DC Input for Dimming Control Built-in Soft-Start Function U-DFN3030-10 Built-in Output Open-Circuit Protection ( Top View ) SO-8, MSOP-8 and U-DFN3030-10: Available in Green Molding Compound (No Br, Sb) with lead Free Finish/ RoHS 1 CTRL 10 SET Compliant 2 9 RSVD NC Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) 8 Halogen and Antimony Free. Green Device (Note 3) 3 NC NC AP8800 7 4 NC SW Applications 5 6 V IN GND Commercial & Industrial Lighting Small LCD Panel Backlight Architecture Detail Lighting Appliances Interior Lighting Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See NOT RECOMMENDED FOR NEW DESIGN AP8800 USE AL8860 and AL8861 Pin Descriptions Pin Number Pin Name Function SO-8 MSOP-8 U-DFN3030-10 Switch Pin. Connect inductor/freewheeling diode here. Minimize trace area at this pin to SW 3 3 4 reduce EMI. GND 4 4 5 GND Pin SET 8 8 10 Set Nominal Output Current Pin. To configure the output current of the device. Dual function dimming control pin. Input voltage of 0.2V or lower forces the device into low current standby mode and shuts off the output. A PWM signal (driven by an open-drain/collector source) allows the output current CTRL 1 1 1 to be adjusted over a wide range up to 100%. An analog voltage between 0.3V and 2.5V adjusts the output current between 25% and 200% of the current set by 0.2V/RS. The input impedance is about 200k, and if the pin is left open V = V CTRL REF 5 5 6 Input Supply Pin. Must be locally bypassed. V IN RSVD 2 2 2 Reserved. Normally connected to Ground NC 6, 7 6, 7 2, 7, 8, 9 No Connection. Functional Block Diagram Absolute Maximum Ratings ( T = +25C, unless otherwise specified.) A Symbol Parameter Rating Unit VIN Pin Voltage -0.3 to +30 V V IN V V Set Voltage Relative to V V -5 to V +0.3 SET IN IN IN VSW SW Voltage -0.3 to +30 V CTRL Pin Input Voltage -0.3 to +5 V V CTRL T Maximum Junction Temperature +125 C J T Maximum Lead Temperature +300 C LEAD T Storage Temperature Range -55 to +125 C ST Caution: Stresses greater than the Absolute Maximum Ratings specified above, may cause permanent damage to the device. These are stress ratings only functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices. 2 of 13 AP8800 April 2018 Diodes Incorporated www.diodes.com Document number: DS31764 Rev. 8 - 3