AL1677 UNIVERSAL, HIGH EFFICIENCY AND ACCURACY LED DRIVER CONVERTER Description Pin Assignments The AL1677 is a universal AC-input (85~277 V ), high-efficiency and AC high-accuracy Buck LED-driver converter. The AL1677 topology (Top View) provides accurate constant current (CC) line and load regulation, operating at boundary conduction mode (BCM) to ease in EMI/EMC 1 8 CS GND qualification and testing to meet the latest regulatory laws. 7 CS ROVP 2 3 6 The AL1677 system removes the auxiliary winding and external high- NC D voltage MOSFET with few external components to create a low bill of 5 D VCC 4 material (BOM) cost solution. The AL1677 has rich protection features to enhance system safety and reliability. With thermal foldback function, the AL1677 can reduce output current when the drivers SO-8 temperature is higher than the setting value. The AL1677 is available in SO-8 package. Features Applications > 90% Efficiency Retrofit LED Lamps Valley Detection to Minimize Switching Loss High Voltage DC-DC LED Driver Universal 85 to 277 V Input Range AC General Purpose Constant Current Source Internal MOSFET up to 500V Tight Current Sense Tolerance : 3% Low Startup Current: 170A Low Operation Current: 100A (Static) Standard Inductor (no auxiliary winding) Internal Protections - Undervoltage Lockout (UVLO) - Leading-Edge Blanking (LEB) - Cycle-by-cycle Overcurrent Protection(OCP) - Output Open/Short Protection(OVP/OSP) - Open-Load and Reload Detection - Thermal Foldback Function(TFP) - Over-Temperature Protection(OTP) SO-8 Package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See AL1677 Typical Applications Circuit + R4 OUT C3 R1 D1 F1 L1 AC R2 Input DB1 C1 4 5 VCC D 6 3 NC D 7 2 ROVP CS C2 GND 8 1 CS U1 AL1677 R3 R5 Pin Descriptions Pin Number Pin Name Function 1 GND Ground 2 ROVP Setting the Open Voltage of the Output 3 NC No Connection 4 VCC Power Supply for the Device 5,6 D Internal High Voltage MOSFETs Drain 7,8 CS Current Sensing Functional Block Diagram 5,6 D 4 VCC OFF Fault V CC VCC STOP Clamp UVLO Management Management OVP OSP OTP VOVP REF VREF OSP TOFF OVP Toff Detection 2 (ZCD) OVP ROVP T OFF V OVP REF S R Q 3 NC 7, 8 Constant LEB CS Current Control 1 Max Ton STOP GND Limit 2 of 13 November 2015 AL1677 Diodes Incorporated www.diodes.com Document number: DS37526 Rev. 1 - 2 NEW PRODUCT