AL1677 UNIVERSAL, HIGH EFFICIENCY AND ACCURACY LED DRIVER CONVERTER Description Pin Assignments The AL1677 is a universal AC-input (85~277 VAC), high-efficiency and (Top View) NEW PRODUCT high-accuracy Buck LED-driver converter. The AL1677 topology provides accurate constant current (CC) line and load regulation, operating at boundary conduction mode (BCM) to ease in EMI/EMC qualification and testing to meet the latest regulatory laws. The AL1677 system removes the auxiliary winding and external highvoltage MOSFET with few external components to create a low bill of 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 driver’s temperature is higher than the setting value. GND 1 8 CS ROVP 2 7 CS NC 3 6 D VCC 4 5 D SO-8 The AL1677 is available in SO-8 package. Features Applications > 90% Efficiency Valley Detection to Minimize Switching Loss Universal 85 to 277 VAC Input Range Internal MOSFET up to 500V Tight Current Sense Tolerance : ± 3% Low Startup Current: 170µA Low Operation Current: 100µA (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: 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. AL1677 Document number: DS37526 Rev. 1 - 2 1 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Typical Applications Circuit R1 R4 D1 + C3 OUT L1 F1 AC Input R2 DB1 NEW PRODUCT C1 4 3 2 1 C2 VCC D NC D ROVP CS GND CS 5 6 7 8 U1 AL1677 R3 R5 Pin Descriptions Pin Number Pin Name 1 GND 2 ROVP 3 NC 4 VCC 5,6 D 7,8 CS Function Ground Setting the Open Voltage of the Output No Connection Power Supply for the Device Internal High Voltage MOSFET’s Drain Current Sensing Functional Block Diagram 5,6 VCC D 4 OFF STOP VCC Fault VCC Clamp Management UVLO Management OVP OSP OTP VOVP_REF VREF OSP OVP OVP ROVP TOFF TOFF Toff Detection (ZCD) 2 VOVP_REF S R NC Q 3 Constant Current Control 7,8 LEB CS 1 GND AL1677 Document number: DS37526 Rev. 1 - 2 STOP Max Ton Limit 2 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) (Note 4) Symbol VCC Unit 18 V AL1677-05BS-13 500 V AL1677-08BS-13 500 V AL1677-10BS-13 500 V AL1677-20BS-13 500 V AL1677-05BS-13 0.5 A AL1677-08BS-13 0.8 A AL1677-10BS-13 1.0 A AL1677-20BS-13 2.0 A Voltage on CS Pin -0.3 to 7 V Voltage on ROVP Pin Power Supply Voltage VD NEW PRODUCT Rating Parameter Voltage on D Pin ID Continuous Drain Current Tc = +25°C VCS -0.3 to 7 V Operating Junction Temperature -40 to +150 °C TSTG Storage Temperature -65 to +150 °C TLEAD Lead Temperature (Soldering, 10 seconds) +260 °C PD Power Dissipation and Thermal Characteristics (TA = +50°C) 0.65 W JA Thermal Resistance (Junction to Ambient) 190 °C/W 2,000 V 200 V VROVP TJ ESD (Human Body Model) ESD (Machine Model) 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) Note: Parameter Ambient Temperature Min Max Unit -40 +105 °C 5. The device can operate normally at +125°C ambient temperature under the condition that the junction temperature is less than +150°C. AL1677 Document number: DS37526 Rev. 1 - 2 3 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Electrical Characteristics Symbol (@TA = +25°C, unless otherwise specified.) Parameter Conditions Min Typ Max Unit – – – 14.5 – – V 8.5 – 16.2 – V – 170 – µA – 100 – µA AL1677-05BS-13 – 24 26 AL1677-08BS-13 – 16 20 AL1677-10BS-13 – 10 12 AL1677-20BS-13 – AL1677-05BS-13 5.4 – 6 – 0.5 AL1677-08BS-13 – – 0.8 AL1677-10BS-13 – – 1.0 AL1677-20BS-13 – – AL1677-05BS-13 500 – 2.0 – AL1677-08BS-13 500 – – AL1677-10BS-13 500 – – AL1677-20BS-13 – – AL1677-05BS-13 500 – – 1 AL1677-08BS-13 – – 1 AL1677-10BS-13 – – 1 AL1677-20BS-13 – – 1 Reference Voltage of ROVP pin – – 0.5 – V Current Sense Reference Minimum tON Maximum tON Maximum tOFF Minimum tOFF (Note 6) – – – – – 0.388 400 – – – 0.400 – 35 200 6 0.412 700 – – – V ns µs µs µs – – +140 – °C – – +170 – °C UVLO Section VTH (ST) VOPR(Min) Vcc_clamp Startup Threshold Minimal Operating Voltage After Turn On – Vcc Clamp Voltage V NEW PRODUCT Standby Current Section IST ICC (OPR) VCC = VTH (ST)-0.5V, Before Start Up Static Start-Up Current Operating Current Internal High Voltage MOSFET RDS(on) IDS VDS IDSS Drain-Source On-State Resistance Continuous Drain-Source Current Drain-Source Voltage Drain-Source Leakage Current Ω A V µA ROVP Section VROVP Current Sense Section VCS-REF tON_MIN tON_MAX tOFF_MAX tOFF_MIN Thermal Foldback and Over-Temperature Protection Section TREG – Notes: Overheating Temperature Regulation (Notes 6 & 8) Shutdown Temperature (Notes 6 & 7 & 8) 6. These parameters, although guaranteed by design, are not 100% tested in production. 7. The device will latch when OTP happen and the device won’t operate constantly at this temperature. 8. This regulation temperature is junction temperature. AL1677 Document number: DS37526 Rev. 1 - 2 4 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Performance Characteristics (Note 9) Start-up Voltage vs. Ambient Temperature Start-up Current vs. Ambient Temperature 16.0 180 15.5 170 Start-up Current (A) NEW PRODUC T Start-up Voltage (V) 15.0 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 80 o Ambient Temperature ( C) 120 Operating Current vs. Ambient Temperature 10.0 140 9.5 130 9.0 Operating Current (A) Minimal operating voltage (V) Minimal Operating Voltage vs. Ambient Temperature 8.5 8.0 7.5 7.0 120 110 100 90 80 6.5 6.0 -40 100 o Ambient Temperature ( C) -20 0 20 40 60 80 100 70 -40 120 -20 0 20 40 60 80 100 120 o Ambient Temperature ( C) Ambient Temperature ( C) VCS Reference vs. Ambient Temperature VROVP Reference vs. Ambient Temperature o 0.50 0.60 0.45 0.40 VROVP Reference (V) VCS Reference (V) 0.55 0.35 0.30 0.50 0.45 0.40 0.25 0.35 0.20 -40 -20 0 20 40 60 80 100 120 0.30 -40 o AL1677 Document number: DS37526 Rev. 1 - 2 -20 0 20 40 60 80 100 120 o Ambient Temperature ( C) Ambient Temperature ( C) 5 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Performance Characteristics (continued) (Note 9) VCC Clamp Voltage vs. Ambient Temperature Vcs Reference vs. Ambient Temperature 0.50 20 0.45 0.40 0.35 Vcs reference (V) NEW PRODUC T VCC Clamp Voltage (V) 18 16 14 0.30 0.25 0.20 0.15 0.10 12 0.05 10 -40 -20 0 20 40 60 80 100 120 0.00 -40 Ambient Temperature ( C) Note: -20 0 20 40 60 80 100 120 140 160 180 o Ambient Temperature ( C) o 9. These electrical characteristics are tested under DC condition. The ambient temperature is equal to the junction temperature of the device. AL1677 Document number: DS37526 Rev. 1 - 2 6 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Application Information Convertor Operation The AL1677 is designed for single-inductance buck application and is an extremely low BOM cost solution widely used in non-isolated situations. The AL1677 operates at boundary conduction mode (BCM) which can get good EMI performance. The device internally integrates a 500V highvoltage MOSFET. The AL1677 adopts a novel method to detect the tOFF time and achieve an extremely low operation current, so the device does not need the auxiliary winding for VCC supply and detecting the tOFF time. It also has good constant current control which can guarantee the NEW PRODUC T system current accuracy. R1 R4 D1 + C3 OUT L1 F1 AC Input R2 DB1 C1 4 3 2 1 C2 R3 VCC D NC D ROVP CS GND CS 5 6 7 8 U1 AL1677 R5 Figure 1 Typical Application Circuit Start-up and Supply Voltage Before start-up, the VCC capacitor C2 is charged by the startup resistors (R1, R2) from the high voltage mains. When the start-up voltage is reached, the AL1677 starts switching. During normal operation, the VCC supply is provided by start-up resisters (R1, R2) and internal source driver circuit. The AL1677 has an internal VCC clamp voltage (typical 16.2V), which is limited by one internal active Zener diode. When VCC voltage drops to below the undervoltage lockout (UVLO), switching is stop, the IC can restart when the voltage on VCC pin is exceeding the startup voltage (VTH (ST)). Protections Undervoltage Lockout (UVLO) When the voltage on the VCC pin drops to below VOPR(Min), the IC stops switching. The IC can restart when the voltage on VCC is exceeds the startup voltage (VTH(ST)) Leading-Edge Blanking (LEB) To prevent false detection of the peak current of the inductor, a blanking time following switch-on is designed. When the internal switch turns on, a short current spike can occur because of the capacitive discharge of the voltage over the drain and source. It is disregarded during the LEB time (tON_MIN). Cycle-by-cycle Overcurrent Protection (OCP) The AL1677 has a built-in peak current detector. It triggers when the voltage on CS pin reaches the peak level VCS_CLAMP. The R5 is connected to the CS pin to sense the current of the inductor. The maximum peak current (IPEAK(MAX))of the inductor can be calculated as below: I PEAK VCS _ REF R5 The detection circuit is activated after the LEB time. When the detection circuit sense the CS voltage is higher than 0.4V, the IC will turn off the switching to limit the output current. It automatically provides protection for the maximum LED current during operation. A propagation delay exists between overcurrent detection and actual source-switch off, so the actual peak current is a little higher than the OCP level set by the R5. Output-Short Protection (OSP) When LED is shorted, the device cannot detect the tOFF time, and the device controls the system operation at 5kHz low frequency. AL1677 Document number: DS37526 Rev. 1 - 2 7 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Application Information (continued) Output Open Protection (OVP) AL1677 has output open-voltage protection controlled when the LED is open, which can prevent the output voltage from increasing to a very high value. This feature can help the system designer select a smaller volume capacitor. The output voltage is set by the external resistor R3, shown in Figure 1. NEW PRODUC T When LED is open, the toff time can be calculated as: toff L1 VCS _ REF VOVP R 5 Where VOVP is the output open voltage, The output voltage is set by R3, and R3 is: R3 VROVP _ REF t off 12 C REF VCS _ REF VROVP _ REF L1 12 C REF VOVP R5 Where VROVP_REF is the internal ROVP pin 0.5V’s reference, CREF is the internal 6pF capacitor. Thermal Foldback Protection (TFP) AL1677 has a thermal foldback function and adopts a self-adaptive control method, which can prevent the system from breaking down due to high temperatures. The overheating temperature is set at +140°C typical. When the junction temperature of the IC is higher than +140°C typical, the device will linearly decrease the internal reference voltage to decrease the output current. As a result of this feature, the device can control the system’s output power at high ambient temperatures, to control the quantity of heat of the system. This enhances the safety of the system at high temperatures. The thermal foldback waveform is shown below: Output current 100% 50% TFOLD=140 OTP Junction temperature/°C Figure 2. Thermal foldback waveform Over-Temperature Protection (OTP) The AL1677 has OTP protection function. When the junction temperature reach to +170°C typical, the IC will trigger an over-temperature protection condition which causes the device to shut down and latched. Once OTP has triggered, the system will resume after the system’s AC source supply has been reset and power up. Design Parameters Setting the Current Sense Resistor R5 The AL1677 uses peak current control method to obtain constant current control and senses the peak current of the inductance cycle by cycle. The sample value is compared with the internal 0.4V reference. When the sampling value is up to 0.4V, the IC control of the internal MOSFET will turn off. The peak current of the inductance is: AL1677 Document number: DS37526 Rev. 1 - 2 8 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Application Information (continued) 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. NEW PRODUC T In no PF buck topology, the system operates at boundary conduct mode. The output current is: 1 I o _ mean I peak 2 Therefore, the current sense resistor R5 is determined: R5 1 VCS _ REF 2 I o _ mean Inductance Selection (L1) The AL1677 controls the system operating at boundary conduction mode, and the systems’ 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 the buck inductance value L1 can be calculated by: L1 ( 2Vin _ rms Vo ) R5 Vo Vcs _ ref 2Vin _ rms f min Where, 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 calculated by: N L1 L1 I peak Ae Bm L1 VCS _ REF Ae Bm R5 Where, Ae is the core effective area. Bm is the maximum magnetic flux density. The AL1677 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, leading the tON to become smaller, when the system’s tON is smaller than tON_MIN, the device cannot detect the peak current of the system, leading to incorrect output current. If the inductance is very large, leading tON to become larger when the system’s tON is larger than the tON_MAX, the system’s output current will decrease because of the limit of the tON_MAX. Therefore, the suitable value of the inductance is very important. The AL1677 tOFF_MIN time is about 6µS and tOFF_MAX time is about 200µs. In buck topology we use the equation VO=L*Ipeak/tOFF. If the inductance is very small, leading the tOFF to become much smaller when the system’s tOFF is smaller than tOFF_MIN, the system will enter DCM mode, and the output current will be incorrect. If the inductance is very large, leading tOFF to become much larger when the system’s tOFF is larger than the tOFF_MAX, the system will enter CCM mode, and the output current will also be incorrect. Therefore, 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 (185~265VAC) 2.3mH 60K(230 VAC) 2.5µS(265 VAC) 11.5µS 42V/100mA (85~265 VAC) 2.5mH 62K(230 VAC) 1.7µs(265 VAC) 12.1µS AL1677 Document number: DS37526 Rev. 1 - 2 9 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Application Information (continued) NEW PRODUC T Recommended Applications The AL1677 integrates different MOSFETs to adapt different wattage applications. The output current is limited by the internal integrated MOSFET, and the SO-8 package’s heat dissipation capability. The minimum output voltage is limited by the LEB time, and is recommended to 15V. The recommended application is given below: Device Output Power Coverage Maximum Output Current (Note 10) Minimum Output Voltage AL1677-05BS-13 ≤5W ≤100mA 15V AL1677-08BS-13 ≤8W ≤120mA 15V AL1677-10BS-13 ≤10W ≤180mA 15V AL1677-20BS-13 ≤15W ≤240mA 15V Note: 10.The higher output current is possible with extra power dissipation solution. AL1677 Document number: DS37526 Rev. 1 - 2 10 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Ordering Information AL1677–XX X XX–13 NEW PRODUC T Current Option 05 : 0.5A 08 : 0.8A 10 : 1.0A 20 : 2.0A Packing Package Mosfet Voltage B: 500V S : SO-8 Part Number Package Code Package AL1677-05BS-13 S AL1677-08BS-13 13 :13" Tape & Reel 13” Tape and Reel Quantity Part Number Suffix SO-8 4,000/Tape & Reel -13 S SO-8 4,000/Tape & Reel -13 AL1677-10BS-13 S SO-8 4,000/Tape & Reel -13 AL1677-20BS-13 S SO-8 4,000/Tape & Reel -13 Marking Information (Top View) 8 7 6 5 Logo YY WW X X 1 AL1677 Document number: DS37526 Rev. 1 - 2 YY : Year : 15,16,17 ~ WW : Week : 01~52; 52 represents 52 and 53 week X X : Internal Code 1677- ZZZ Part Number 1677-05B for 0.5A/500V 1677-08B for 0.8A/500V 1677-10B for 1.0A/500V 1677-20B for 2.0A/500V 2 3 4 11 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 Package Outline Dimensions (All dimensions in mm (inch).) 0.254 Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for the latest version. E1 E A1 NEW PRODUC T L Gauge Plane Seating Plane Detail ‘A’ 7°~9° h 45° Detail ‘A’ A2 A A3 b e D SO-8 Dim Min Max A 1.75 A1 0.10 0.20 A2 1.30 1.50 A3 0.15 0.25 b 0.3 0.5 D 4.85 4.95 E 5.90 6.10 E1 3.85 3.95 e 1.27 Typ h 0.35 L 0.62 0.82 0° 8° All Dimensions in mm Suggested Pad Layout Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version X Dimensions X Y C1 C2 C1 Value (in mm) 0.60 1.55 5.4 1.27 C2 Y AL1677 Document number: DS37526 Rev. 1 - 2 12 of 13 www.diodes.com November 2015 © Diodes Incorporated AL1677 IMPORTANT NOTICE NEW PRODUC T 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). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated website, harmless against all damages. Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel. Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks. This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the final and determinative format released by Diodes Incorporated. LIFE SUPPORT Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright © 2015, Diodes Incorporated www.diodes.com AL1677 Document number: DS37526 Rev. 1 - 2 13 of 13 www.diodes.com November 2015 © Diodes Incorporated