NOT RECOMMENDED FOR NEW DESIGN USE AL8860 and AL8861 AP8801 500mA LED STEP-DOWN CONVERTER Description Pin Assignments The AP8801 The AP8801 is a step-down DC/DC converter designed to drive LEDs (Top View) 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 SET 1 8 CTRL identical LED currents resulting in uniform brightness and eliminating GND 2 7 GND the requirement for ballast resistors. The AP8801 switches at AP8801 frequency up to 700kHz. NC 3 6 SW V 4 5 SW IN This allows the use of small-size external components, hence minimizing the PCB area needed. SO-8 Maximum output current of AP8801 is set via an external resistor (Top View) 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 pin. An input voltage of 0.2V or lower at CTRL shuts down the output SET 1 8 CTRL at SW and puts the device into a low-current standby state. 2 GND 7 GND AP8801 NC 3 6 SW V 4 5 SW IN MSOP-8 Features Applications Commercial & Industrial Lighting LED Driving Current up to 500mA Operating Input Voltage up to 48V Small LCD Panel Backlight High Efficiency up to 92% Appliances Interior Lighting High Switching Frequency up to 700kHz Architecture Detail Lighting 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) Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Notes: 1. EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. All applicable RoHS exemptions applied. 2. See AP8801 Pin Descriptions Pin Name Functions SW Switch Pin. Connect inductor/freewheeling diode here, minimizing track length at this pin to reduce EMI. GND GND Pin SET Set Nominal Output Current Pin. 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 to be adjusted over a wide range CTRL 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/R . S The input impedance is about 50k, and if the pin is left open, it is V = V CTRL REF V Input Supply Pin. Must be locally bypassed. IN NC No Connection Functional Block Diagram Fig. 1 Block Diagram Absolute Maximum Ratings ( T = +25C, unless otherwise specified.) A Symbol Parameter Rating Unit V V Pin Voltage -0.3 to +50 V IN IN V SW Voltage -0.3 to +50 V SW V CTRL Pin Input Voltage -0.3 to +6 V CTRL V SET Voltage +0.3 to -5 V SENSE T J Junction Temperature +150 C T Lead Temperature Soldering +300 C LEAD T Storage Temperature Range -65 to +150 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 15 March 2019 AP8801 Diodes Incorporated www.diodes.com Document number: DS31765 Rev. 9 - 3