NOT RECOMMENDED FOR NEW DESIGN NO ALTERNATIVE AL1673 UNIVERSAL FLYBACK AND BUCK-BOOST SINGLE STAGE DIMMABLE LED DRIVER Description Pin Assignments The AL1673 is a high performance single stage Flyback/Buck-Boost (Top View) converter, targeting dimmable LED lighting application. It is operating at BCM mode which results in good EMI and efficiency. 8 CS 1 COMP The AL1673 can support multiple dimming modes. When a 0.3~2.4V DC signal is applied on APWM pin, the device will operate in analog GND 2 7 APWM EP dimming mode. When a digital signal is applied on APWM pin, the DRAIN 3 6 FB device works at PWM dimming mode. DRAIN 4 5 VCC The AL1673 features low start-up current and low operation current. It integrates multiple protections including over voltage, short circuit, over current and over temperature protection. It also integrates SO-8EP 600V/2A high voltage MOSFET. The AL1673 is available in SO-8EP package. Applications General LED Lighting Driver with Dimming Function General Purpose Constant Current Source Features Smart LED Lighting Valley Switching for Low Switching Loss Low Start-Up Current High PF and Low THD High Efficiency Tight LED Current Variation Range Tight Output Open Voltage Variation Range Integrates 600V/2A MOSFET Support Both PWM Dimming and Analog Dimming PWM Dimming Range:3% to 100% at 1kHz PWM Frequency Analog Dimming and PWM-to-DC Dimming Range:18% to 100% Internal Protections Under Voltage Lock Out (UVLO) Output Over Voltage Protection (OVP) Output Short Protection (OSP) Over Current Protection (OCP) Thermal Fold-back Protection (TFP) Over Temperature Protection (OTP) Low System Cost Package: SO-8EP 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 AL1673 Typical Applications Circuit L1 T1 D2 F1 R10 C5 RTH D1 AC R4 OUT D3 R3 VR1 C4 C2 input C1 DB1 CVCC R5 T1.aux CY 5 6 R6 VCC FB 7 PWM/DC APWM 3 Signal DRAIN 8 COMP 4 DRAIN CS GND R COMP 2 1 R CCOMP CS AL1673 Flyback Application Circuit L1 F1 RTH D1 AC R4 OUT VR1 R3 C4 C2 input C1 + CVCC DB1 R5 L2 5 6 VCC R6 FB 7 PWM/DC APWM 3 Signal DRAIN 8 COMP 4 DRAIN GND CS Rcomp D2 2 1 RCS Ccomp AL1673 Buck-Boost Application Circuit Pin Descriptions Pin Number Pin Name Function Current sense pin, connect this pin to the source of the primary 1 CS switch 2 GND Ground 3,4 DRAIN Drain of internal MOS Supply voltage of gate driver and control circuits of the IC 5 VCC 6 FB The feedback voltage sensing from the auxiliary winding Analog dimming input pin or PWM signal input pin in PWM 7 APWM dimming mode 8 COMP Loop compensation pin 9 Exposed Pad Drain of internal MOS 2 of 15 February 2021 AL1673 Diodes Incorporated www.diodes.com Document number: DS39540 Rev. 2 - 3 +