A Product Line of Diodes Incorporated AP1684 AC/DC, HIGH PF, HIGH EFFICIENCY LED DRIVER CONTROLLER Description Pin Assignments The AP1684 is a high performance AC/DC power factor corrected LED driver controller which is driving high voltage bipolar transistor. The device uses Pulse Frequency Modulation (PFM) technology to regulate output current while achieving high power factor and low THD. It operates as a boundary condition mode (BCM) buck controller which is good for EMI. (Top View) The AP1684 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. 8 VCC RI 2 7 OUT RM 3 6 GND 4 5 FB (SO-8/ M Package) Features The AP1684 is available in SO-8 package. Applications LED Bulb Lamp LED Down Light GU10/E27 Other Non-dimmable LED Lighting Low Start-up Current High PF and Low THD (PF > 0.9, THD < 30%) High Efficiency up to 92% BCM Mode Output Current Accuracy on IC Level: ±2% Tight LED Open Voltage Valley-mode Switching to Minimize the Transition Loss BJT Transistor Driver Dynamic Base Driver Control Open-load and Reload Detection Internal Protections: Under Voltage Lock Out (UVLO) Leading-edge Blanking (LEB) Output Short Protection Output Open Protection Over Temperature Protection Low System Cost SO-8 Package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) Notes: 1 CS The AP1684 features low start-up current, low operation current and high voltage driving bipolar transistor. It adopts dynamic base driver control technology and valley on switching mode to achieve high efficiency. It also has rich protection features including over voltage, short circuit, over temperature protection. NC 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 L1 C1 R9 C2 AC Input + C4 OUT D2 F1 R3 VR1 D1 T1 R4 DB1 2 R1 R2 AP1684 Document number: DS36547 Rev. 3 - 2 3 RI R5 8 5 VCC FB AP1684 C3 OUT 7 RM 4 GND CS 6 1 of 13 www.diodes.com Q1 R6 R7 R8 February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Pin Descriptions Pin Number Pin Name Function 1 NC No connection 2 RI The initial Tonp tuning resistor 3 RM Set the operating mode 4 CS Primary current sensing 5 FB The feedback voltage sensing from the auxiliary winding 6 GND Ground 7 OUT Gate driver output 8 VCC Supply voltage of gate driver and control circuits of the IC Functional Block Diagram VCC 8 CS_OCP Vdd Power_EN Vref Regulator & Bias PRO Protection & Latch FB_CV FB_OVP VCC_OVP FB RI RM 5 Tons Detector Tons 2 Set Initial Tonp & Set the IC Working in BCM 3 CC_CTRL S Logic TONP_CTRL Q PFM Driver 7 6 CS 4 Constant Turn-on Time Generation AP1684 Document number: DS36547 Rev. 3 - 2 2 of 13 www.diodes.com OUT R GND February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified. Note 4) Symbol Parameter Rating Unit VCC Power Supply Voltage -0.3 to 35 V IOUT Driver Output Current 150 mA VCS Voltage at CS to GND -0.3 to +7 V VFB FB Input Voltage -40 to +10 V 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 = +50°C) 0.65 W JA Thermal Resistance (Junction to Ambient) 160 °C/W – ESD (Human Body Model) 2000 V – ESD (Charged-device Model) ±1000 V TJ 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 7 25 V TA Ambient Temperature -40 +105 °C AP1684 Document number: DS36547 Rev. 3 - 2 3 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Electrical Characteristics (@TA = +25°C, unless otherwise specified.) Symbol Parameter Conditions Min Typ Max Unit UVLO Section VTH (ST) VOPR (Min) VCC_OVP – Start-up Threshold – 18 19 20 V Minimum Operating Voltage After turn on 5.5 6.5 7.5 V VCC OVP Voltage – 30 32 34 V VCC Delatch Voltage (Note 5) – 3 4 5 V – – 20 μA Standby Current Section IST VCC = VTH (ST)-0.5V, Start-up Current Before start up Operating Current Static – 900 1300 μA IOUT Output Current (Note 5) VCS_PEAK = 1V – – 60 mA VOS UVLO Saturation Voltage VCC = 0 to VCC-ON, ISINK = 10mA – – 1.1 V VCS_REF Current Sense Reference – – 1 – V VCS_CLAMP Current Sense Reference Clamp – 1.2 1.4 – V Minimum tONP – 700 – 1000 ns Delay to Output (Note 5) – 50 150 250 ns Feedback Pin Input Leakage Current VFB = 2V – – 4 μA VFB_CV FB CV Threshold – 3.8 4 4.2 V VFB_OVP FB OVP Threshold – 4.5 6 7.5 V System Output Current on Final Test Board – – – ±2 % ICC (OPR) Drive Output Section Current Sense Section tONP_MIN tD(H-L) Feedback Input Section IFB Output Current – 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. AP1684 Document number: DS36547 Rev. 3 - 2 4 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Performance Characteristics Supply Current vs. Supply Voltage CV Threshold vs. Supply Voltage 1000 4.2 900 4.1 700 CV Threshold (V) Supply Current (A) 800 600 500 400 300 4.0 3.9 3.8 200 3.7 100 0 3.6 0 5 10 15 20 25 30 6 8 10 12 Supply Voltage (V) 14 16 18 20 22 24 26 28 30 Supply Voltage (V) Start-up Voltage vs. Ambient Temperature Minimal Operating Voltage vs. Ambient Temperature 7.2 19.2 Minimal Operating Voltage (V) 7.1 Start-up Voltage (V) 18.8 18.4 18.0 17.6 17.2 7.0 6.9 6.8 6.7 6.6 6.5 6.4 6.3 16.8 -40 -20 0 20 40 60 80 100 6.2 -40 120 -20 0 Start-up Current vs. Ambient Temperature 60 80 100 120 Operating Current vs. Ambient Temperature 0.5 1000 0.4 950 Operating Current (A) Start-up Current (A) 40 Ambient Temperature ( C) Ambient Temperature ( C) 0.3 0.2 900 850 800 0.1 0.0 -40 20 o o -20 0 20 40 60 80 100 120 750 -40 AP1684 Document number: DS36547 Rev. 3 - 2 -20 0 20 40 60 80 100 120 o o Ambient Temperature ( C) Ambient Temperature ( C) 5 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Performance Characteristics (Cont.) CV Threshold vs. Ambient Temperature FB Leakage Current vs. Ambient Temperature 2.25 4.50 2.00 FB Leakage Current (A) CV Threshold (V) 4.25 4.00 3.75 3.50 1.75 1.50 1.25 3.25 3.00 -40 -20 0 20 40 60 80 100 120 1.00 -40 Document number: DS36547 Rev. 3 - 2 0 20 40 60 80 100 120 Ambient Temperature ( C) Ambient Temperature ( C) AP1684 -20 o o 6 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Application Information The AP1684 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 AP1684 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 C1 R9 C2 AC Input + C4 OUT D2 F1 R3 VR1 D1 T1 R4 DB1 2 R1 R2 3 RI R5 8 5 VCC FB AP1684 C3 OUT Q1 7 RM 4 GND CS 6 R6 R7 R8 Figure 1. Typical Application Circuit Design Parameters Setting the Current Sense Resistor R8 As the AP1684 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 AP1684 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, and considering the limit of the BJT’s operating frequency, 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 m in Where, Vo is the output voltage. Vin_rms is the RMS value of the input voltage. AP1684 Document number: DS36547 Rev. 3 - 2 7 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 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: 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 AP1684 adopts constant on-time control method, the AP1684 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 R8 2U in _ rms _ max 1010 The system operation mode is determined by R2, to guarantee the system working at BCM mode, resistance R2 is generally selected as R2≤R1. Valley on Control Method The valley on function can provide low turn-on switching losses for buck converter. The voltage across the collector and emitter of the BJT 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 AP1684 Document number: DS36547 Rev. 3 - 2 8 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Application Information (Cont.) According to Figure 2, when the falling edge of 0.1V is sensed by the FB pin, the AP1684 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 VCC RFB1 FB RFB2 AP1684 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 BJT 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 AP1684 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 AP1684 can startup successfully when the ambient temperature is less than +150°C. Recommended Applications The AP1684 is designed to drive BJT as the power switch, because of the BJT’s current limit, the maximum output current is limited. In buck structure, the output voltage has some limitation because of the dead zone. The device is designed for single voltage application, so the recommended application is given in the table below. AC Power Input Output Voltage Range Max Output Current Low Mains Input 20V to 70V 200mA (13005) High Mains Input 20V to 120V 200mA (13005) Components Selection Guide If the system’s output spec is changed, please refer to the design sheet of the AP1684 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 R3, C3, T1 EMI Pass EN 55022 class B with 6DB margin L1, C1, C2 AP1684 Document number: DS36547 Rev. 3 - 2 9 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Ordering Information AP1684 X XX – XX Product Name RoHS/Green Package Packing M : SO-8 TR : Tape & Reel G1 : Green Diodes IC’s Pb-free products with "G1" suffix in the part number, are RoHS compliant and green. Package Temperature Range SO-8 -40°C to +105°C Part Number AP1684MTR-G1 Marking ID 1684M-G1 Packing 4000/13”Tape & Reel Marking Information (Top View) 1684 M-G1 YWWAXX AP1684 Document number: DS36547 Rev. 3 - 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. 10 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Package Outline Dimensions (All dimensions in mm(inch).) (1) Package Type: SO-8 4.700(0.185) 5.100(0. 201) 7° ~ 9° 0.320(0. 013) TYP 1.350(0. 053) 1.750(0. 069) 8° 8° ~ 9° 7° 0.600(0. 024) 0.725(0. 029) D 5.800(0. 228) 6.200(0. 244) 1.270(0. 050) TYP D 20:1 0.300(0. 012) R0.150(0.006) 0.100(0. 004) 1.000(0. 039) TYP 3.800(0. 150) Option 1 4.000(0. 157) 0.300(0. 012) 0.150(0. 006) 0.250(0. 010) Option 1 0° 8° 1° 7° 0.510(0. 020) R0.150(0.006) 0.450(0. 017) 0.820(0. 032) Option 2 0.350(0. 014) TYP Note: Eject hole , oriented hole and mold mark is optional . AP1684 Document number: DS36547 Rev. 3 - 2 11 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 Suggested Pad Layout (1) Package Type: SO-8 Grid placement courtyard G Z Y E X Dimensions Z (mm)/(inch) G (mm)/(inch) X (mm)/(inch) Y (mm)/(inch) E (mm)/(inch) Value 6.900/0.272 3.900/0.154 0.650/0.026 1.500/0.059 1.270/0.050 AP1684 Document number: DS36547 Rev. 3 - 2 12 of 13 www.diodes.com February 2014 © Diodes Incorporated A Product Line of Diodes Incorporated AP1684 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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