AL1672

AL1672

Document overview

• Manufacturer or author: Diodes Incorporated
• PDF pages: 14

Technical content

Features

• 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/4A 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) Pin Assignments (Top View) CS GND DRAIN DRAIN COMP APWM FB VCC EP SO-8EP

Applications

• General LED Lighting Driver with Dimming Function
• General Purpose Constant Current Source
• Smart LED Lighting Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen - and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. NOT RECOMMENDED FOR NEW DESIGN NO ALTERNATIVE PART

Document number: DS39344 Rev. 2 - 3 2 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Typical Applications Circuit OUT + VCC FB DRAIN CS GND C RTHAC Input F 1 VR 1 DB1 COMP CCOMP RCS DRAIN

7 APWM

Pin Number Pin Name Function

1 CS Current sense pin, connect this pin to the source of the primary

2 GND Ground

3,4 DRAIN Drain of internal MOS

5 VCC Supply voltage of gate driver and control circuits of the IC

6 FB The feedback voltage sensing from the auxiliary winding

7 APWM Analog dimming input pin or PWM signal input pin in PWM dimming

8 COMP Loop compensation pin

9 Exposed Pad Drain of internal MOS

Document number: DS39344 Rev. 2 - 3 3 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Functional Block Diagram DIM Control APWM Valley Detector Logical Control UVLO &Bias VREF S D Q Driver COMP FB OVP CS VCC DRAIN G m OTP GND 3,4,9 8 2 Temperature Detector TFP OTP VREF VREF TFP AL1672 Block Diagram

Document number: DS39344 Rev. 2 - 3 4 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) (Note 4) Symbol Parameter Rating Unit VCC Power Supply Voltage -0.3 to 30 V VCS Voltage at CS to GND -0.3 to 7 V VFB FB Input Voltage -0.3 to 7 V VCOMP Loop Compensation Pin -0.3 to 7 V VDRAIN Drain Voltage of Internal MOS 600 V IDS Continuous Drain Current TC = +25°C 4 A VAPWM Voltage at APWM to GND -0.3 to 7 V TJ Operating Junction Temperature -40 to +150 °C TSTG Storage Temperature -65 to +150 °C TLEAD Lead Temperature (Soldering, 10 sec) +300 °C PD Power Dissipation at TA=+50°C (Note 5) 1.53 W θJA Thermal Resistance (Junction to Ambient) (Note 5) 65 °C/W θJC Thermal Resistance (Junction to Case) (Note 5) 22.4 °C/W ESD (Human Body Model) 2000 V ESD (Machine Model) 200 V Notes: 4. Stresses greater than those listed under “Absolute Maxi mum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Condi tions” is not implied. Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability. All voltages unless otherwise stat ed and measured with respect to GND. 5. Device mounted on 2"x2" FR-4 substrate PCB, 2oz copper, with minimum recommended pad layout. Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Symbol Parameter Min Max Unit TA Ambient Temperature (Note 6) -40 +105 °C Note: 6. The device may operate normally at +125°C ambient temperature under the condition not trigger temperature protection.

Document number: DS39344 Rev. 2 - 3 5 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Electrical Characteristics (@TA = +25°C, unless otherwise specified.) Symbol Parameter Condition Min Typ Max Unit UVLO Section Startup Threshold Voltage VCC_TH – 17 18.5 20 V Minimal Operating Voltage VOPR_MIN After Turn On 7 7.8 8.5 V VCC OVP Voltage VCC_OVP – 25 27 29.9 V Standby Current Section Startup Current IST VCC = VCC_TH -0.5V, Before Start Up – 0.8 – μA Operating Current ICC FB CS connect to GND, CGATE=100pF – 1 – mA Shunt Current in OVP Mode ICC_OVP VCC>VCC_OVP 3 5 7 mA Switch Time Parameter Maximum On Time tON_MAX – – 25 – μs Maximum Off Time tOFF_MAX – – 35 – μs Minimum Off Time tOFF_MIN – 1 2 6 μs Maximum Frequency fMAX – 120 150 230 kHz Internal CS Reference Internal Reference Voltage VREF – 0.291 0.3 0.309 V Primary Current Clamp Voltage VCS_OCP – 1.1 1.2 1.3 V Error Amplifier Gm Gm Trans-Conductance – 10 16.7 22 μA/V ISOURCE Amplifier Source Current – 7 10 15 μA Feedback Input Section FB CV Threshold VFB_CV – 1.4 1.5 1.6 V APWM Section PWM Dimming Low Threshold Voltage VAPWM_L – – 0.3 – V PWM Dimming High Threshold Voltage VAPWM_H – – 2.4 – V Linear Dimming Range on APWM – – 0.3 – 2.4 V Internal High Voltage MOSFET RDS(ON) Drain-Source on State Resistance – – 2 2.5 Ω VDS Drain-Source Break- Down Voltage – 600 – – V IDSS Drain-Source Leakage Current VDS= 600V ,VGS=0V – – 1 μA Thermal Fold-Back Section Thermal Fold-Back Temperature (Note 7) TREG – – +145 – °C Over Temperature Protection Section Shutdown Temperature Notes: 7. These parameters, although guaranteed by design, are not 100% tested in production. 8. The device will latch when OTP happens and the device won’t operate constantly at this temperature.

Document number: DS39344 Rev. 2 - 3 6 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Performance Characteristics (Note 9) Startup Threshold Voltage vs. Ambient Temperature Minimum Operating Voltage vs. Ambient Temperature Operating Current vs. Ambient Temperature FB CV Threshold vs. Ambient Temperature Internal Reference Voltage vs. Ambient Temperature FB CV Threshold vs. V CC Voltage Internal Reference Voltage vs. V CC Voltage Note: 9. These electrical characteristics are tested under DC condition. The ambient temperature is equal to the junction temperatur e of the device. -40 -20 0 20 40 60 80 100 120 18.0 18.5 19.0 19.5 20.0 VCC_TH (V) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 1.1 1.2 1.3 1.4 1.5 1.6 ICC (mA) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 1201.1 1.2 1.3 1.4 1.5 1.6 VFB_CV (V) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 7.2 7.4 7.6 7.8 8.0 8.2 VOPR_MIN (V) Ambient Temperature ( o 12 15 18 21 24 271.2 1.3 1.4 1.5 1.6 1.7 1.8 VFB_CV (V) VCC Voltage(V) -40 -20 0 20 40 60 80 100 120284 288 292 296 300 304 308 VREF (mV) Ambient Temperature ( o 12 15 18 21 24 27 270 280 290 300 310 320 330 VREF (mV) VCC Voltage(V)

Document number: DS39344 Rev. 2 - 3 7 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Functional Description and Application Information The AL1672 is a constant current high PF BUCK converter, targeting LED lighting applications. The device integrates 600V/4 A high voltage MOSFET, which will help to cost down the whole system. High power factor is achieved by constant on time operation. In order to reduce the switching losses and improve EMI performance, quasi -resonant switching mode is applied. The AL1672 integrates multiple protections including UVLO protection, V CC over voltage protection, output open voltage protection, over current protection, thermal fold- back protection and over temperature protection. The AL1672 can support multiple dimming modes including analog dimming mode and PWM dimming. OUT VCC FB DRAIN CS GND RTHAC Input F 1 VR 1 DB1 COMP CCOMP RCS DRAIN Figure 1: AL1672 BUCK Application Circuit Start-Up After AC supply is powered on, the capacitor C VCC across VCC and GND pin will be charged up by BUS voltage through a start -up resistor R2. Once VCC reaches VCC_TH, the internal blocks start to work. V CC will be supplied by V BUS until the auxiliary winding of transformer could supply enough energy to maintain VCC above VOPR_MIN. If VCC voltage is lower than VOPR_MIN switch will be turned off. After V CC exceeds VCC_TH, the drive block won’t start to switch on /off signals until V COMP is over the initial voltage V COMP_ST which can be programmed by RCOMP. The formula is shown as below. Such design can program startup on time to reduce the startup time or reduce the output overshoot current. Where VCOMP_ST is the pre-charged voltage of COMP pin, RCOMP is shown as Figure 1. Generally, a big capacitance of C5 is necessary to achieve high power factor and stabilize the system loop (1μF~2μF is recommended); the pre- charged voltage in start-up procedure can be programmed by RCOMP. Protections 1. Output-Open Protection (OVP) The output voltage is reflected by the voltage on transformer’s auxiliary winding. Both F B pin and VCC pin of IC integrate over voltage protection function. When there is a rapid line and load transient, the output voltage may exceed the regulated value. If V CC exceeds V CC_OVP or V FB exceeds VFB_CV, the over voltage protection will be triggered, switch will be turned off and V CC will be discharged. Once V CC is below VOPR_MIN., the IC will shut down and be powered on again by BUS voltage through start up resistor. Thus, output over voltage depends on the minimum voltage between both OVP protections’ limitation. It can be gotten by below formula. 56, 6 PP OVP CC OVP AUX AUX NN RRV Min V N NR

Document number: DS39344 Rev. 2 - 3 8 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Functional Description and Application Information (Cont.) Where VOVP is the output over voltage setting; R5 and R6 is shown as Figure.1, it is the resistor divider from auxiliary winding; NAUX is the turns of L2 auxiliary winding; NP is turns of L2 main winding. VCC_OVP is OVP Voltage of VCC. 2. Output Short Protection (OSP) When the output is shorted, the output voltage is clamped to zero. The output voltage of the auxiliary winding, which is proportional to the output winding, will drop down too. Once V CC is below VOPR_MIN, the IC will shut down and power on again by the BUS voltage through the start up resistor. 3. Over Current Protection (OCP) The AL1672 has a build-in cycle by cycle over current protection of primary inductor current. When CS pin voltage reaches the voltage V CS_OCP, switch will be turn off until next switch period. The maximum peak current (IPEAK (MAX)) of the inductor can be calculated as below: ( ) _CS OCP PEAK MAX CS Where VCS_OCP means primary current clamp voltage that is 1.25V. RCS is current sense resister which is shown as figure1. 4. Thermal Fold-Back Protection (TFP) The AL1672 has thermal fold-back function: it adopts self -adaptive control method which can prevent the system from breaking down caused by over temperature. The overheating temperature is set at +145°C. When the temperature of the IC is higher than this point; the device will decrease the voltage reference of the CS linearly till OTP happens. By this way, the device can limit system’s input power at high amb ient temperature, preventing system’s temperature increase further. 5. Over Temperature Protection (OTP) The AL1672 has build-in over temperature protection (OTP) function. When the temperature goes up to +165°C, the over temperature protection will be triggered, which leads to a latch mode protection. When OTP happens, the system need to be powered off and on again to restart. Output Constant-Current Control According to the definition of mean output current, the mean output current can be obtained as below. O MEAN PI I dt πθ θπ arcsin

2 IN RMS

V θ = Where IO_MEAN is the mean output current; IP is the peak current of inductance; VIN_RMS is the rate input voltage; VO is the output voltage; It can be described by following formula: REF P CSV I R dt πθ θπ = ⋅⋅ ∫

Document number: DS39344 Rev. 2 - 3 10 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Functional Description and Application Information (Cont.) Operation Parameters Design Setting the Current Sense Resistor RCS The current sense resistance can be calculated as following: REF CS O MEAN VR I= ⋅ Where IO_MEAN is the mean output current; RCS is current sense resister which is shown as figure1; VREF is internal reference voltage that is equal to 0.3V; Buck Inductance Selection (L2) The switching frequency is not constant for the AL1672 due to boundary conduction mode. To s et the minimum switching frequency fMIN at the crest of the minimum AC input, primary inductance can be obtained by below formula. _ _ ( 2 sin( ) ) 2 2 IN MIN O O O MEAN IN MIN MIN V t V dt VL I Vf πθ θ π = ⋅⋅ ⋅⋅ Where VIN_MIN is the minimum input AC voltage; IO_MEAN is the mean output current; VO is the output voltage; fMIN is the minimum switching frequency at the crest of the minimum AC input; For boundary conduction mode and constant on time method, the peak current of primary inductance can be calculated as below. (2 ) IN MIN O O P IN MIN MIN V VVI LV f ⋅ −⋅= Where VIN_MIN is the minimum input AC voltage; IP is the max peak current of inductance. VO is the output voltage; fMIN is the minimum switching frequency at the crest of the minimum AC input. According to the Faraday’s Law, the winding number of the inductance can be calculated by: PP P em LIN AB Where Ae is the core effective area. Bm is the maximum magnetic flux density.

Document number: DS39344 Rev. 2 - 3 11 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672

Ordering Information

40: 4.0A AL1672-X X X–X MOSFET VoltageCurrent Option C: 600V SP: SO-8EP Package Packing 13: Tape & Reel Part Number Package Code Package 13” Tape and Reel Quantity Part Number Suffix AL1672-40CSP-13 SP SO-8EP 2500/Tape & Reel -13 Marking Information 1672-ZZZ (Top View) YY WW X X E Logo WW : Week : 01~52; 52 YY : Year : 15, 16, 17~ X X : Internal Code 8 7 6 5 1 2 3 4 represents 52 and 53 week Part Number 1672-40C for 600V/4A E : SO-8EP

Document number: DS39344 Rev. 2 - 3 12 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Package Outline Dimensions (All dimensions in mm.) (1) Package Type: SO-8EP 5.800(0.228) 6.200(0.244) 1.270(0.050) 0.400(0.016) 3.800(0.150) 4.000(0.157) 0.150(0.006) TYP 0.250(0.010) 0.150(0.006) 1.350(0.053) 1.550(0.061) 2.110(0.083) 2.710(0.107) 2.750(0.108) 3.402(0.134) 5.100(0.201) Note: Eject hole, oriented hole and mold mark is optional. 0.300(0.012)

Document number: DS39344 Rev. 2 - 3 13 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 Suggested Pad Layout (1) Package Type: SO-8EP G E X Y Y1 Z Dimensions Z (mm)/(inch) G (mm)/(inch) X (mm)/(inch) Y (mm)/(inch) (mm)/(inch) (mm)/(inch) E (mm)/(inch)

Document number: DS39344 Rev. 2 - 3 14 of 14 www.diodes.com February 2021 © Diodes Incorporated AL1672 IMPORTANT NOTICE 1. DIODES INCORPORATED AND ITS SUBSIDIARIES (“DIODES”) MAKE NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO ANY INFORMATION CONTAINED IN THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON -INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 2. The Information contained herein is for informational purpose only and is provided only to illustrate the operation of Diodes products described herein and application examples. Diodes does not assume any liability arising out of the application or use of thi s document or any product described herein. This document is intended for skilled and technically trained engineering customers and users who design with Diodes products. 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