NOT RECOMMENDED FOR NEW DESIGN - NO ALTERNATE PART AP1686 LOW-POWER OFF-LINE PSR LED CONTROLLER Description Pin Assignments The AP1686 is a high performance AC/DC power supply controller for (Top View) LED lighting application. The device uses Pulse Frequency Modulation (PFM) method to build discontinuous conduction mode Pin 1 Mark (DCM) flyback power supplies. The AP1686 provides accurate constant voltage, constant current (CV/CC) regulation without requiring an opto-coupler and the OUT 1 6 FB secondary control circuitry. It also eliminates the need of loop compensation circuitry while maintaining good stability. The AP1686 5 GND GND 2 can achieve excellent regulation and high average efficiency, yet meets no-load consumption less than 30mW. VCC 3 4 CS It also has an adjustable built-in line compensation function to achieve tight CC. SOT-23-6 The AP1686 is available in SOT-23-6 package. Features Applications Primary Side Control for Tight Constant Current and Constant LED Driver Voltage 30mW No-load Input Power Bipolar Junction Transistor (BJT) Driving Open Circuit Protection Over Voltage Protection Short Circuit Protection SOT-23-6 Package 1 of 10 AP1686 April 2018 Diodes Incorporated www.diodes.com Document number: DS40909 Rev. 1 - 3 NOT RECOMMENDED FOR NEW DESIGN - NO ALTERNATE PART AP1686 Typical Applications Circuit D2 T1 V + O + + C1 R1 + D1 C4 R10 C2 Ns Np V - R2 O 3 VCC 4 1 Na CS OUT Q1 R6 AP1686 6 FB GND 2,5 R7 R LINE Rs Pin Descriptions Pin Number Pin Name Function The OUT pin is used to turn on and turn off the power switch. When turning on the power switch, 1 OUT the OUT pin will output 30mA source current to support the base current of the power BJT. When turning off the power switch, the resistance between the OUT and GND will become to 5 The GND pin is the ground of the IC. When the power BJT is turned off, a fast reverse sinking 2, 5 GND current to the gate of BJT will flow out from this pin. Attention should be paid to in the PCB layout The VCC pin supplies the power for the IC. In order to get the correct operation of the IC, a 3 VCC capacitor with low ESR should be placed as close as possible to the VCC pin The CS is the current sense pin of the IC. The IC will turn off the power BJT according to the 4 CS voltage on the CS pin. When the power BJT is on, a current is output from the CS pin which is proportional to the line voltage to realize the function of line compensation 6 FB The CV and CC regulation are realized based on the voltage sampling of this pin 2 of 10 AP1686 April 2018 Diodes Incorporated www.diodes.com Document number: DS40909 Rev. 1 - 3