AL1678-20B/10B/08B UNIVERSAL, 500V BUCK LED DRIVER Description Pin Assignments NEW PRODUCT The AL1678-20B/10B/08B is a universal AC input (85 to 277 VAC), high efficiency and high accuracy Buck LED driver. The AL167820B/10B/08B topology provides accurate constant current over line and load regulation with tight tolerance ±3%, operating at boundary conduction mode (BCM) to ease in EMI/EMC qualification and testing to meet the latest regulatory laws. (Top View) The AL1678-20B/10B/08B single Buck stage system works with a single winding inductor and High voltage MOSFET included, therefore, can use fewer external components and create a low bill of material (BOM) cost solution. The AL1678-20B/10B/08B has rich protection features to enhance the system safety and reliability. It has thermal fold back function, which can reduce the output current when the driver’s temperature is higher than the setting value. 7 Drain 3 6 LC 4 5 CS OUT 1 VCC 2 ROVP GND SO-7 The AL1678-20B/10B/08B is available in SO-7 package. Applications Features > 90% Efficiency Valley Switching to Achieve Low Switching Loss Universal 85 to 277 VAC Input Range Internal MOSFET up to 500V Tight Current Sense Tolerance: ±3% Low Start-up Current: 170µA Low Operation Current: 100µA (Static) Single Winding Inductor Internal Protections Under Voltage Lock Out (UVLO) Leading-edge Blanking (LEB) Output Open/Short Protection Open-load and Reload Detection Thermal Fold-back Function Over Temperature Protection (OTP) SO-7 Package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) Notes: Retrofit LED Lamps High Voltage DC-DC LED Driver General Purpose Constant Current Source 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. Typical Applications Circuit R1 R4 D1 C3 + OUT L1 F1 AC Input R2 DB1 C1 R3 C2 1 OUT Drain 7 2 VCC 6 3 ROVP LC 4 GND 5 CS U1 AL1678-20B/10B/08B AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 1 of 13 www.diodes.com R5 April 2015 © Diodes Incorporated AL1678-20B/10B/08B NEW PRODUCT Pin Descriptions Pin Number Pin Name Function 1 OUT Internal power MOSFET’s source 2 VCC Power supply for the device 3 ROVP 4 GND 5 CS Current sensing 6 LC Line compensation pin 7 Drain Setting the open voltage of the output Ground Internal high voltage MOSFET’s drain Functional Block Diagram Drain VCC 7 2 STOP UVLO Fault VCC VCC Clamp Management Management OTP 3 1 ROVP OUT toff Detection (ZCD) VCC OVP Output OVP Q S R 5 CS LEB Constant Current Control Max ton Limit 6 STOP LC 4 GND AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 2 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) (Note 4) Symbol Rating Unit 18 V AL1678-20B 500 V AL1678-10B 500 V AL1678-08B 500 V AL1678-20B 2.0 A AL1678-10B 1.0 A AL1678-08B 0.8 A Voltage on CS Pin -0.3 to 7 V Voltage on ROVP Pin -0.3 to 7 V Operating Junction Temperature -40 to +150 ºC TSTG Storage Temperature -65 to +150 ºC TLEAD Lead Temperature (Soldering, 10 sec) +260 ºC 0.65 W Thermal Resistance (Junction to Ambient) 190 ºC/W ESD (Human Body Model) 2000 V ESD (Machine Model) 200 V VCC NEW PRODUCT VDrain ID VCS VROVP TJ PD θJA Parameter Power Supply Voltage Voltage on Drain Pin Continuous Drain Current (TC = +25oC) Power Dissipation and Thermal Characteristics (TA = +50oC) – Note 4: Stresses greater than those listed under “Absolute Maximum 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 Conditions” is not implied. Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability. Recommended Operating Conditions Symbol TA Note 5: Parameter Ambient Temperature (Note 5) Min Max Unit -40 +105 °C The device can operate normally at +125°C ambient temperature under the condition that the junction temperature is less than +150°C. AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 3 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Electrical Characteristics Symbol (@TA = +25°C, unless otherwise specified.) Parameter Conditions Min Typ Max Unit UVLO Section Startup Threshold – – 14.5 – V VOPR(Min) Minimal Operating Voltage After Turn On – 8.5 – V VCC_Clamp VCC Clamp Voltage – – 16.2 – V – 170 – µA Static – 100 – µA AL1678-20B – 5.4 6 AL1678-10B – 10 12 16 20 NEW PRODUCT VTH (ST) Standby Current Section IST ICC(OPR) Start-up Current Operating Current VCC = VTH (ST)-0.5V, Before Start Up Internal High Voltage MOSFET RDS(ON) Drain-Source on State Resistance AL1678-08B Ω AL1678-20B – – 2.0 AL1678-10B – – 1.0 AL1678-08B – – 0.8 AL1678-20B 500 – – AL1678-10B 500 – – AL1678-08B 500 – – – – 1 – – 1 – – 1 – – +140 – Reference Voltage of ROVP Pin – – 0.46 – V VCS-REF Current Sense Reference – 0.388 0.400 0.412 V tON_MIN Minimum tON – 400 – 700 ns tON_MAX Maximum tON – – 35 – µs tOFF_MAX Maximum tOFF – – 200 – µs tOFF_MIN Minimum tOFF (Note 6) – – 6 – µs Delay to Output (Note 6) – 50 150 250 ns – – +170 – °C IDS VDS Continuous Drain-Source Current Drain-source Voltage VDS = 500V, VGS = 0, TC = +25oC (AL1678-20B) IDSS Drain-source Leakage Current VDS = 500V, VGS = 0, TC = +25oC (AL1678-10B) VDS = 500V, VGS = 0, TC = +25oC (AL1678-08B) A V µA Thermal Foldback Section And ROVP Section TREG VROVP Overheating Temperature Regulation (Note 6) o C Current Sense Section tD(H-L) Over Temperature Protection Section – Notes: Shutdown Temperature (Notes 6 & 7) 6. These parameters, although guaranteed by design, are not 100% tested in production. 7. The device will latch when OTP happens and the device won’t operate constantly at this temperature. AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 4 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Performance Characteristics (Note 8) Start-up Voltage vs. Ambient Temperature Start-up Current vs. Ambient Temperature 16.0 180 15.5 170 Start-up Current (A) Start-up Voltage (V) 14.5 14.0 13.5 13.0 160 150 140 130 12.5 12.0 -40 -20 0 20 40 60 80 100 120 -40 120 -20 0 20 40 60 o Ambient Temperature ( C) 100 120 Operating Current vs. Ambient Temperature 10.0 140 9.5 130 9.0 Operating Current (A) Minimal Operating Voltage (V) 80 o Ambient Temperature ( C) Minimal Operating Voltage vs. Ambient Temperature 8.5 8.0 7.5 7.0 120 110 100 90 80 6.5 6.0 -40 -20 0 20 40 60 80 100 70 -40 120 -20 0 20 40 60 80 100 120 o Ambient Temperature ( C) o Ambient Temperature ( C) VCS Reference vs. Ambient Temperature VROVP Reference vs. Ambient Temperature 0.50 0.60 0.45 0.55 0.40 0.50 VROVP Reference (V) VCS Reference (V) NEW PRODUCT 15.0 0.35 0.30 0.25 0.20 -40 0.45 0.40 0.35 -20 0 20 40 60 80 100 120 0.30 -40 o AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 -20 0 20 40 60 80 100 120 o Ambient Temperature ( C) Ambient Temperature ( C) 5 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Performance Characteristics (Note 8) VCC Clamp Voltage vs. Ambient Temperature VCS Reference vs. Ambient Temperature 0.50 20 0.45 0.40 0.35 VCS Reference (V) NEW PRODUCT VCC Clamp Voltage (V) 18 16 14 12 0.30 0.25 0.20 0.15 0.10 0.05 10 -40 -20 0 20 40 60 80 100 0.00 -40 120 -20 0 20 40 60 80 100 120 140 160 180 o Ambient Temperature ( C) o Ambient Temperature ( C) Integrated 500V/2A MOSFET SOA (Note 9) ID, Drain Current (A) ID, Drain Current (A) Integrated 500V/1A MOSFET SOA (Note 9) VDS, Drain-to-source Voltage (V) Notes: VDS, Drain-to-source Voltage (V) 8. These electrical characteristics are tested under DC condition. The ambient temperature is equal to the junction temperature of the device. 9. The MOSFET SOA curve is tested under the TO-251 package type. AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 6 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Application Information The AL1678-20B/10B/08B is designed for single inductor buck application, it is an extremely low BOM cost solution widely used in non-isolate situation. It operates as boundary conduction mode (BCM) which can get a good EMI performance. The device internally integrates a 500V high voltage MOSFET. The AL1678-20B/10B/08B adopts a novel method to detect the tOFF time and realize an extremely low operation current, so the device does not need the auxiliary winding for VCC supply and detects the tOFF time. It also has a good constant current control which can NEW PRODUCT guarantee the system current accuracy. R1 R4 D1 C3 + OUT L1 F1 AC Input R2 DB1 C1 R3 C2 1 OUT Drain 7 2 VCC 6 3 ROVP LC 4 GND 5 CS U1 AL1678-20B/10B/08B R5 Figure 1. Typical Application Circuit Design Parameters Setting the Current Sense Resistor R5 The AL1678-20B/10B/08B uses peak current control method to obtain constant current control and senses the peak current of the inductor cycle by cycle. The sample value is compared with the internal 0.4V reference, when the sample value is up to 0.4V, the IC control the internal MOSFET turned off. So the peak current of the inductance is I peak VCS _ REF R5 Where, VCS_REF is the reference of the current sense, and the typical value is 0.4V. R5 is the current sense resistor. In no PF buck topology, the system operates at boundary conduct mode, so the output current is I o _ mean 1 I peak 2 So, the current sense resistor R5 is determined: R5 1 VCS _ REF 2 I o _ mean Inductance Selection (L1) The AL1678-20B/10B/08B controls the system operating at boundary conduction mode, and the system’s operating frequency does not keep constant because of the fluctuation of the bus voltage, set the minimum switching frequency fmin at the maximum bus voltage, and buck inductance value L1 is: AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 7 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Application Information (Cont.) L1 ( 2Vin _ rms Vo ) R5 Vo VCS _ REF 2Vin _ rms f m in Where, NEW PRODUCT Vo is the output voltage. Vin_rms is the RMS value of the input voltage. According to the faraday’s law of induction, the winding number of the inductance can be got: L1 I peak N L1 Ae Bm L1 VCS _ REF Ae Bm R5 Where, Ae is the core effective area. Bm is the maximum magnetic flux density. The AL1678-20B/10B/08B has designed the minimum tON time and maximum tON time, the tON_MIN is about 700ns and the tON_MAX time is about 35µs. In buck topology we can get the equation Vin_rms-VO = L*Ipeak/tON. If the inductance is very small, it leads to the tON becoming smaller, when the system’s tON is smaller than tON_MIN, the device can’t detect the peak current of the system leading to wrong output current. While if the inductance is very large, it leads to the t ON becoming longer, when the system’s tON is longer than the tON_MAX, the system will trigger OVP, and the LED will flicker. So the suitable value of the inductance is very important. The AL1678-20B/10B/08B has also designed the minimum tOFF time and the maximum tOFF time, the tOFF_MIN time is about 6µs and tOFF_MAX time is about 200µs. In buck topology we can get the equation V O = L*Ipeak/tOFF. If the inductance is very small, it leads to the t OFF becoming much smaller, when the system’s tOFF is smaller than tOFF_MIN, the system will enter DCM mode, and the output current will be wrong. While if the inductance is very large, it leads to the tOFF becoming much longer, when the system’s tOFF is longer than the tOFF_MAX, the system will enter CCM mode, and the output current will also be wrong. So the suitable value of the inductance is very important. Consider these parameters, two examples of the typical application inductance is recommended as below: System Spec Inductance Value System Frequency tON_MIN tOFF 60V/150mA (85 to 277VAC) 2.3mH 60KHz (230VAC) 2.5µs (265VAC) 11.5µs 42V/100mA (85 to 277VAC) 2.5mH 62KHz (230VAC) 1.7µs (265VAC) 12.1µs Fault Protection Setting Output Open Voltage The AL1678-20B/10B/08B has output open voltage protection, and the output voltage is controlled when the LED is open, which can prevent the output voltage increasing to a very high value. This feature can help the system designer to select a smaller volume capacitor. The output voltage is set by the external resistor R3 shown in Figure 1. When the LED is open, the tOFF time can be calculated as tOFF L1 VCS _ REF VOVP R 5 Where, AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 8 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Application Information (Cont.) VOVP is the output open voltage. When the LED is open, the output voltage is set by R3, and R3 is NEW PRODUCT R3 VROVP _ REF tOFF 40 CREF VCS _ REF VROVP _ REF L1 40 CREF VOVP R5 Where, VROVP_REF is the internal ROVP pin 0.46V’s reference. CREF is the internal 6pF capacitor. Output Short Protection When the LED is shorted, the device can’t detect the demagnetization time, the device controls the system operation at 5K’s low frequency. Thermal Fold Back Function AL1678-20B/10B/08B has thermal fold back function, it adopts self-adaptive control method which can prevent the system breaking down caused by high temperature. The overheating temperature is set at +140°C, when the temperature of the IC is higher than +140°C the device will decrease the reference of the CS linearly till OTP happens. By this way, the device can control the system’s output power at high ambient temperature, so the quantity of heat of the system can be controlled and temperature of the system is controlled, So the safety of the system at high temperature is got enhanced. Over Temperature Protection The AL1678-20B/10B/08B has OTP protection function. When the temperature is increased to +170°C, the IC will trigger over temperature protection which leads to a latch operating mode. When OTP happens, the system can restart under the condition that the system’s AC source supply is powered off first. Recommended Applications The AL1678-20B/10B/08B integrates different MOSFET to adapt different wattage application. And the output current is limited by the internal integrated MOSFET and the SO-7 package’s heat dissipation capability. And the minimum output voltage is limited by the LEB time, the minimum output voltage is recommended to 15V. So the recommended application is given below: Note 10: Device Output Power Coverage Maximum Output Current (Note 10) Minimum Output Voltage AL1678-20B ≤15W ≤240mA 15V AL1678-10B ≤10W ≤180mA 15V AL1678-08B (Note 11) ≤8W ≤120mA 15V The higher output current is possible with extra power dissipation solution. AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 9 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Ordering Information AL1678 - XX X XX - 13 NEW PRODUCT Product Name Current Option MOSFET Voltage Package Packing 08 : 0.8A 10 : 1.0A 20 : 2.0A B: 500V S7 : SO-7 13 :13" Tape & Reel 13” Tape and Reel Part Number Package Code Package Quantity Part Number Suffix AL1678-20BS7-13 S7 SO-7 4000/Tape & Reel -13 AL1678-10BS7-13 S7 SO-7 4000/Tape & Reel -13 AL1678-08BS7-13 (Note 11) S7 SO-7 4000/Tape & Reel -13 Note 11: The AL1678-08BS7-13 is still under development and not orderable. Marking Information (Top View) 7 6 5 Logo Part Number 1678-20B for 2.0A/500V 1678-10B for 1.0A/500V 1678-08B for 0.8A/500V 1678 - ZZZ YY WW X X 1 AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 YY : Year : 15,16,17 ~ WW : Week : 01~52; 52 represents 52 and 53 week X X : Internal Code 2 3 10 of 13 www.diodes.com 4 April 2015 © Diodes Incorporated AL1678-20B/10B/08B Package Outline Dimensions (All dimensions in mm (inch).) (1) Package Type: SO-7 5.800(0.228) 1.350(0.053) 1.750(0.069) NEW PRODUCT 6.200(0.244) 0.330(0.013) 0.510(0.020) 2.54(0.100) TYP 4.700(0.185) 5.100(0.201) 1.270(0.050) TYP 0.080(0.003) 0.250(0.010) 3.800(0.150) 4.000(0.157) 1.250(0.049) 1.500(0.059) 0.350(0.014) TYP 0° 8° Option 1 0.450(0.017) 0.800(0.031) 45° 0.150(0.006) 0.250(0.010) Option 2 Note: Eject hole, oriented hole and mold mark is optional. AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 11 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B Suggested Pad Layout Package Type: SO-7 NEW PRODUCT (1) G Z E1 Y X E Dimensions Z (mm)/(inch) G (mm)/(inch) X (mm)/(inch) Y (mm)/(inch) E (mm)/(inch) E1 (mm)/(inch) Value 6.900/0.272 3.900/0.154 0.650/0.026 1.500/0.059 1.270/0.050 2.540/0.100 AL1678-20B/10B/08B Document number: DS37637 Rev. 1 - 2 12 of 13 www.diodes.com April 2015 © Diodes Incorporated AL1678-20B/10B/08B IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 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