A Product Line of Diodes Incorporated AP1685 OFFLINE, HIGH PF, HIGH EFFICIENCY LED DRIVER IC Description Pin Assignments NEW PRODUCT The AP1685 is a high performance AC/DC power factor corrector for mains dimmable LED driver applications. The device uses Pulse Frequency Modulation (PFM) technology to regulate output current while achieving high power factor and low THD. It operates as a BCM (Boundary Conduction Mode) which is good for EMI. (Top View) The AP1685 internally integrates a 500V high voltage MOSFET which can realize a lower BOM cost. The AP1685 provides accurate constant current (CC) regulation while removing the opto-coupler and secondary control circuitry. It also eliminates the need of loop compensation circuitry while maintaining stability. It can meet the requirement of IEC6100-3-2 harmonic standard. S 1 7 Drain CS 2 RI 3 6 VCC GND 4 5 FB SO-7 The AP1685 features low start-up current, low operation current. It adopts valley on switching mode to achieve high efficiency. It also has rich protection features including over voltage, short circuit, over temperature protection. The AP1685 is available in SO-7 package. Applications Non-dimmable LED drivers Features Notes: Boundary Conduction Mode (BCM) Operation to Achieve Highefficiency High PF and Low THD (PF>0.9, THD<30%) High Efficiency Low Start-up Current Tight LED Current Tight LED Open Voltage Valley-mode Switching to Minimize the Transition Loss Internal Integrated 2.5A/500V MOSFET can Cover up to 10W Easy EMI Internal Protections: Under Voltage Lock Out (UVLO) Leading-edge Blanking (LEB) Output Short Protection Output Open Protection Over Temperature Protection Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) 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. AP1685 Document number: DS37311 Rev. 1 - 2 1 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Typical Applications Circuit L1 R9 C2 C1 + C4 F1 R2 NEW PRODUCT OUT D2 VR1 AC Input T1 D1 DB1 R4 C3 R5 VCC R1 FB Drain RI R6 S GND CS R7 U1 AP1685 R8 Typical Buck Application with Auxiliary Winding D1 ZD1 L1 R8 L2 R7 F1 R2 Drain CS DB1 AC VR1 R5 S C1 VCC C2 RI D2 AP1685 GND R9 FB + C4 OUT R6 C3 R1 Typical Floating Buck Application without Auxiliary Winding AP1685 Document number: DS37311 Rev. 1 - 2 2 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Pin Descriptions Pin Name 1 S 2 CS Current sensing 3 RI Setting the initial on time 4 GND 5 FB 6 VCC Supply voltage of gate driver and control circuits of the IC. 7 Drain Internal MOSFET’s Drain NEW PRODUCT Pin Number Function Internal MOSFET’s Source Ground The feedback voltage from auxiliary winding Functional Block Diagram VCC 6 Vdd Power_EN Vref FB RI 5 3 Regulator & Bias PRO Protection & Latch CS_OCP FB_CV FB_OVP VCC_OVP 7 Tons Detector Tons Set Initial Tonp CC_CTRL S PFM Logic Q TONP_CTRL Vcs_valley Driver R Vcsmax 1 CS 2 Drain Constant Turn-on Time Generation S 4 GND AP1685 Document number: DS37311 Rev. 1 - 2 3 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Absolute Maximum Ratings (Note 4) (@TA = +25°C, unless otherwise specified.) NEW PRODUCT Symbol Parameter Rating Unit VCC Power Supply Voltage -0.3 to 35 V VCS Voltage at CS to GND -0.3 to 7 V VFB FB Input Voltage -40 to 10 V VDrain Voltage on Drain 500 V ID Continue Drain Current TC = +25oC 2.5 A 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 (TA = +50C) 0.65 W θJA Thermal Resistance (Junction to Ambient) 160 °C/W – ESD (Human Body Model) ±2000 V – ESD (Machine Model) ±200 V 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 Parameter Min Max Unit VCC Power Supply Voltage 8 25 V TA Ambient Temperature -40 +105 °C AP1685 Document number: DS37311 Rev. 1 - 2 4 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Electrical Characteristics (@TA = +25°C, unless otherwise specified.) Symbol Parameter Conditions Min Typ Max Unit UVLO Section VTH (ST) NEW PRODUCT VOPR (Min) VCC_OVP – Start-up Threshold – 13 14.5 16 V Minimum Operating Voltage After turn on 5.5 6.5 7.5 V VCC OVP Voltage – 27 29 31 V VCC Delatch Voltage (Note 5) – 3 4 5 V – – 20 µA Standby Current Section IST ICC (OPR) VCC = VTH (ST)-0.5V, Start-up Current Before start up Operating Current Static – 900 1300 µA Current Sense Reference – – 1 – V Current Sense Reference Clamp – 1.2 1.4 – V Minimum tONP – 700 – 1000 ns Delay to Output (Note 5) – 50 150 250 ns VFB = 2V – – 4 µA Current Sense Section VCS_REF VCS_CLAMP tONP_MIN tD(H-L) Feedback Input Section IFB Feedback Pin Input Leakage Current VFB_CV FB CV Threshold – 3.8 4 4.2 V VFB_OVP FB OVP Threshold – 4.5 6 7.5 V RDS(ON) Drain-Source On-State Resistance VGS = 10V, ID = 1.25A – – 6 Ω VBR(Drain) Drain-Source Breakdown Voltage VGS = 0V, ID = 250µA 500 – – V Drain-Source Leakage Current VDS = 500V, VGS = 0V – – 1 µA – – – ±2 % Internal MOSFET Section IDSS Output Current – System Output Current On Final Test Board Over Temperature Protection Section – Shutdown Temperature (Note 5) – +150 – – °C – Temperature Hysteresis (Note 5) – – +20 – °C Note 5: These parameters, although guaranteed by design, are not 100% tested in production. . AP1685 Document number: DS37311 Rev. 1 - 2 5 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Performance Characteristics CV Threshold vs. Supply Voltage Start-up Voltage vs. Ambient Temperature 16.0 4.2 15.5 4.1 Start-up Voltage (V) CV Threshold (V) 3.9 3.8 14.5 14.0 13.5 13.0 3.7 12.5 3.6 6 8 10 12 14 16 18 20 22 24 26 12.0 -40 28 -20 0 20 40 60 80 100 120 o Supply Voltage (V) Ambient Temperature ( C) Minimal Operating Voltage vs. Ambient Temperature Start-up Current vs. Ambient Temperature 7.2 2.0 7.1 1.8 Minimal Operating Voltage (V) 7.0 Start-up Current (A) 6.9 6.8 6.7 6.6 6.5 1.6 1.4 1.2 1.0 6.4 0.8 6.3 6.2 -40 -20 0 20 40 60 80 100 0.6 -40 120 -20 0 20 o 60 80 100 120 Ambient Temperature ( C) Operating Current vs. Ambient Temperature CV Threshold vs. Ambient Temperature 4.50 1000 4.25 CV Threshold (V) 900 800 700 600 500 -40 40 o Ambient Temperature ( C) Operating Current (A) NEW PRODUCT 15.0 4.0 4.00 3.75 3.50 3.25 -20 0 20 40 60 80 100 120 3.00 -40 Document number: DS37311 Rev. 1 - 2 0 20 40 60 80 100 120 Ambient Temperature ( C) Ambient Temperature ( C) AP1685 -20 o o 6 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Performance Characteristics (Cont.) FB Leakage Current vs. Ambient Temperature Supply Current vs. Supply Voltage 2.25 1000 800 Supply Current (A) FB Leakage Current (A) NEW PRODUCT 2.00 1.75 1.50 1.25 1.00 -40 600 400 200 -20 0 20 40 60 80 100 0 0 120 Ambient Temperature ( C) AP1685 Document number: DS37311 Rev. 1 - 2 4 8 12 16 20 24 28 Supply Voltage (V) o 7 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Application Information The AP1685 is designed for single voltage application, and it features high power factor correction (PFC), low total harmonic distortion (THD), low BOM cost and good EMI performance. The device can be widely used in non-dimmable LED application such as GU10, bulb lamps, down lamp, etc. The AP1685 adopts constant on time control method within one AC cycle to achieve the high power factor and low THD. The control scheme is very simple, the power factor correction effectiveness is obvious, and the constant current control is also good enough. L1 R9 C1 C2 + C4 NEW PRODUCT F1 R2 AC Input OUT D2 VR1 T1 D1 DB1 R4 C3 R5 VCC R1 FB Drain RI R6 S GND U1 AP1685 CS R7 R8 Figure 1. Typical Application Circuit Design Parameters Setting the Current Sense Resistor R8 As the AP1685 adopts constant on time control method, the current of the inductance will follow the input voltage to get a sinusoidal wave. The current sense pin CS of the AP1685 will sense the peak current of the inductance by sensing the voltage dropped on the current sense resistor R8, and the constant current control is realized by controlling the peak current. In buck structure, when the VO is higher than VIN, no energy will be transferred from input to output which is called dead zone, and considering the dead zone of buck structure, the output current can be calculated as below: I o _ mean k 1 Vcs _ ref R8 Where, Vcs_ref is the reference of the current sense, and the typical value is 1V. k is the current modification coefficient, and the value of k is approximate to be 0.7. So, the current sense resistor R8 is determined: R8 k V cs _ ref I o _ mean Transformer Selection (T1) The non-isolated buck circuit in Figure 1 is usually selected, and the system is operating at boundary conduction mode. The system’s operating frequency does not keep constant, the minimum switching frequency at the crest is set as fmin, and then the buck inductance value L can be got: L ( 2 Vin _ rms Vo ) R8 Vo Vcs _ ref 2 Vin _ rms f min Where, VO is the output voltage. Vin_rms is the RMS value of the input voltage. AP1685 Document number: DS37311 Rev. 1 - 2 8 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Application Information (Cont.) The next step is determining the transformer’s winding turns number, the worst case operation condition of transformer is at the peak voltage area of sine waveform input voltage where the current of across the inductance is the maximum value. The transformer design should be based on the worst case operation condition to guarantee that the transformer is not saturated. According to Ferrari's law of electromagnetic induction, the winding turns number of the buck inductance NL is: NEW PRODUCT NL L I pk Ae Bm L Vcs _ ref Ae Bm R8 Where, Ae is the core effective area. Bm is the maximum magnetic flux density. The auxiliary winding is power supply for VCC, the winding turns number Naux is: N aux N L Vcc Vo V d Where, VCC is the power supply voltage for IC from auxiliary winding. Vd is the voltage drop of the freewheel diode. Setting the Initial On Time As the AP1685 adopts constant on-time control method, the AP1685 will generate an initial on time to start a working cycle. If the initial on time is longer than the rated on time, overshoot will happen which could damage the LED. And a good system performance does not permit overshoot, so the appropriate initial on time should be guaranteed. And initial on time is determined by resister R1 shown in Figure 1. According to initial on time generation mechanism, the ton_initial is ton _ initial 80 R11012 s To guarantee the system with no overshoot phenomenon, the resistor is selected R1 1.25 L 1010 R8 2U in _ rms _ max Valley on Control Method The valley on function can provide low turn-on switching losses for buck converter. The voltage across the drain and source of the power MOSFET is reflected by the auxiliary winding of the buck transformer. The voltage is sensed by the FB pin. FB 0.1V 1µs Valley Figure 2. Valley on Control AP1685 Document number: DS37311 Rev. 1 - 2 9 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Application Information (Cont.) According to Figure 2, when the falling edge of 0.1V is sensed by the FB pin, the AP1685 will see the tOFF time is over and delay 1µs to start a new operating cycle. In this way we can realize valley on function. Fault Protection Over Voltage Protection and Output Open Protection NEW PRODUCT VCC RFB1 FB RFB2 AP1685 Figure 3. OVP Circuit The output voltage is sensed by the auxiliary winding voltage of the buck transformer, the VCC pin and FB pin provide over voltage protection function. When the output is open or large transient happens, the output voltage will exceed the rated value. When the voltage of VCC cap exceeds Vcc_ovp or VFB_CV, the over voltage is triggered and the IC will discharge VCC. When the VCC is below the UVLO threshold voltage, the IC will start a new work cycle and the VCC cap is charged again by start resistance. If the over voltage condition still exists, the system will work in hiccup mode. Output Short Protection When the output is shorted, the output voltage will be clamped at 0. At this condition, V CC will drop down without auxiliary winding for power supply. And the VCC will drop to UVLO threshold voltage, the IC will shut down and restart a new operating cycle, and the VCC is charged by startup resistance. When the VCC is higher than Vcc_start voltage, the IC will output a bunch of pulse to control power MOSFET on and off, which will consume the energy stored in the VCC cap, because of no VCC supply from the auxiliary winding, the VCC will drop down to VCC UVLO threshold voltage again. If output short condition still exists, the system will operate in hiccup mode. Over Temperature Protection The AP1685 has two kinds of over temperature protection processes. First, the system is operating normally, the ambient temperature is changed to +170°C suddenly, the IC will trigger over temperature protection which leads to a latch work mode. Second, if the system starts, the over temperature protection will be triggered when the ambient temperature is higher than +150°C. So the AP1685 can startup successfully when the ambient temperature is less than +150°C. Recommended Applications The AP1685 is a device which internally integrates a MOSFET, the output current is limited by the internal integrated MOSFET, using this device can cover up to 10W’s application meanwhile the output current is less than 200mA. Components Selection Guide If the system’s output spec is changed, please refer to the design sheet of the AP1685 and select the compatible system parameter. When the system needs to be adjusted slightly, please refer to the table below and adjust the value of the related component. Item Description Related Components IO LED current R8 Output Current Ripple Small current ripple is good for LED life C4 ton_initial System initial on time, used to start up the system R1 Output Open Voltage Setting the output voltage when the LED is open R5, R6 Line Compensation To get a good line regulation R7, R9 Startup Time System startup time R2, C3, T1 EMI Pass EN 55022 class B with 6DB margin L1, C1, C2 AP1685 Document number: DS37311 Rev. 1 - 2 10 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Ordering Information AP1685 X XX – XX NEW PRODUCT Product Name RoHS/Green Package Packing M : SO-7 TR : Tape & Reel G1 : Green Package Temperature Range Part Number Marking ID Packing SO-7 -40°C to +105°C AP1685MTR-G1 1685M-G1 4000/13’’Tape & Reel Marking Information (Top View) 1685 M-G1 YWWAXX AP1685 Document number: DS37311 Rev. 1 - 2 First and Second Lines: Logo and Marking ID Third Line: Date Code Y: Year WW: Work Week of Molding A: Assembly House Code th th XX: 7 and 8 Digits of Batch No. 11 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 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 0.100(0.004) 0.250(0.010) 3.800(0.150) 4.000(0.157) 0.190(0.007) 0.250(0.010) 0° 8° 1.250(0.049) 1.500(0.059) 0.450(0.017) 0.800(0.031) Note: Eject hole, oriented hole and mold mark is optional. AP1685 Document number: DS37311 Rev. 1 - 2 12 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 Suggested Pad Layout NEW PRODUCT (1) Package Type: SO-7 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 AP1685 Document number: DS37311 Rev. 1 - 2 13 of 14 www.diodes.com September 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1685 IMPORTANT NOTICE NEW PRODUCT 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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