A Product Line of Diodes Incorporated APR3415 SECONDARY SIDE SYNCHRONOUS RECTIFICATION SWITCHER Description Pin Assignments NEW PRODUCT APR3415 is a secondary side Combo IC, which combines an NChannel MOSFET and a driver circuit designed for synchronous rectification (SR) in DCM operation. It also integrates output voltage detect function for primary side control system. (Top View) The N-Channel MOSFET has been optimized for low gate charge, low RDS(ON), fast switching speed and body diode reverse recovery performance. DRISR 1 8 DRAIN VDET 2 7 DRAIN The synchronous rectification can effectively reduce the secondary side rectifier power dissipation and provide high performance solution. By sensing MOSFET drain-to-source voltage, APR3415 can output ideal drive signal with less external components. It can provide high performance solution for 5V output voltage application. AREF 3 6 GND VCC 4 5 GND Same as AP4341, APR3415 detects the output voltage and provides a periodical signal when the output voltage is lower than a certain threshold. By fast response to secondary side voltage, APR3415 can effectively improve the transient performance of primary side control system. SO-8 Applications • The APR3415 is available in SO-8 package. • Adapters/Chargers for Cell/Cordless Phones, ADSL Modems, MP3 and Other Portable Apparatus Standby and Auxiliary Power Supplies Features • Synchronous Rectification for DCM Operation Flyback • Eliminate Resonant Ring Interference • Fast Detector of Supply Voltages • Fewest External Components Totally Lead-free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) 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. Typical Applications Circuit C21 + C23 C22 + R21 APR3415 R23 DRAIN GND DRAIN GND VDET VCC DRISR AREF R24 C24 RAREF CAREF APR3415 Document number: DS36738 Rev. 7 - 2 1 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 NEW PRODUCT Pin Descriptions Pin Number Pin Name Function 1 DRISR Synchronous rectification MOSFET drive 2 VDET Synchronous rectification sense input and dynamic function output, connected to DRAIN through a resistor 3 AREF Program a voltage reference with a resistor from AREF to GND, to enable synchronous rectification MOSFET drive signal 4 VCC Power supply, connected with system output 5, 6 GND Source pin of internal MOSFET, connected to Ground 7, 8 DRAIN Drain pin of internal MOSFET Functional Block Diagram VCC 4 VREF VDET Integrator (VDET-VCC)*tONP IOVP Dynamic OVP IAREF tONPDET Counter 3 AREF DRISR OSC 1 SRDRIVER 5, 6 GND 7, 8 DRAIN 2 VDET APR3415 Document number: DS36738 Rev. 7 - 2 2 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Absolute Maximum Ratings (Note 4) Symbol VCC Supply Voltage Value Unit -0.3 to 7.5 V Voltage at VDET, DRAIN Pin -2 to 50 V VAREF, VDRISR Voltage at AREF, DRISR Pin -0.3 to 6 V NEW PRODUCT VDET, VDRAIN ID Continuous Drain Current 15 A IDM Pulsed Drain Current 60 A PD Power Dissipation at TA=+25ºC 0.7 W θJA Thermal Resistance (Junction to Ambient) (Note 5) Thermal Resistance (Junction to Case) (Note 5) 170 ºC/W 24 ºC/W +150 ºC -65 to +150 ºC +300 ºC θJC TJ Notes: Parameter Operating Junction Temperature TSTG Storage Temperature TLEAD Lead Temperature (Soldering, 10 sec) 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. 5. FR-4 substrate PC board, 2oz copper, with 1 inch2 pad layout. Recommended Operating Conditions Symbol Parameter Min Max Unit VCC Supply Voltage 3.3 6 V TA Ambient Temperature -40 +85 ºC APR3415 Document number: DS36738 Rev. 7 - 2 3 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Electrical Characteristics Symbol (@TA = +25°C, VCC =5V, unless otherwise specified.) Parameter Conditions Min Typ Max Unit Supply Voltage ( VCC Pin ) Startup Current VCC=VSTARTUP-0.1V – 100 150 μA Operating Current VDET pin floating VCC=VTRIGGER+20mV 40 100 150 μA Startup Voltage – 2.6 3.1 3.4 V UVLO – 2.3 2.8 3.1 V Internal Trigger Voltage – 5.25 5.3 5.35 V Duty Cycle – 4 8 12 % Oscillation Period VCC=5V 18 30 37.5 μs Internal Trigger Current VCC=VTRIGGER, VCC/VDET pin is separately connected to a 20Ω resistor 30 – 42 mA tDIS Minimum Period – 18 30 37.5 ms VDIS Discharge Voltage – 5.28 5.44 5.52 V IDIS Discharge Current VCC=VDIS+0.1V 1.5 3 4.5 mA ISTARTUP IOP NEW PRODUCT VSTARTUP – Dynamic Output Section/Oscillator Section VTRIGGER – tOSC ITRIGGER Trigger Discharger Gap – 30 110 – mV VOVP Overshoot Voltage for Discharge – 5.8 5.9 6.0 V IOVP Overshoot Current for Discharge VCC=VOVP+0.1V, VCC pin is connected to a 20Ω resistor 40 – 100 mA VDIS-VTRIGGER Synchronous Voltage Detect VTHON Gate Turn On Threshold – 0 – 1 V VTHOFF Gate Turn Off Threshold – -20 -12.5 -5 mV tDON Turn On Delay Time From VTHON to VDRISR=1V – 70 130 ns tDOFF Turn Off Propagation Delay Time From VTHOFF to VDRISR=3V – 100 150 ns tRG Gate Turn On Rising Time From 1V to 3V, CL=4.7nF – 50 100 ns tFG Gate Turn Off Falling Time From 3V to 1V, CL=4.7nF – 50 100 ns (VDET-VCC)*tONP = 25Vµs 0.9 1.8 2.7 (VDET-VCC)*tONP = 50Vµs – – 6.5 3.7 – – V tLEB_S Minimum On Time tLEB_L VDRISR_HIGH VS_MIN tOVP_LAST Kqs μs Drive Output Voltage VCC=5V SR Minimum Operating Voltage (Note 6) – – – 4.5 V Added OVP Discharge Time – – 2.0 – ms (Note 7) (VDET-VCC)*tONP = 25Vµs 0.325 – 0.515 mA*μs Notes: 6. This item specifies the minimum SR operating voltage of VIN_DC, VIN_DC≥NPS*VS_MIN. 7. This item is used to specify the value of RAREF. APR3415 Document number: DS36738 Rev. 7 - 2 4 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Electrical Characteristics (@TA =+25°C, unless otherwise specified. Cont.) NEW PRODUCT MOSFET Static Characteristics Parameters Symbol Drain to Source Breakdown Voltage VDSS(BR) Gate Threshold Voltage VGS(TH) Zero Gate Voltage Drain Current Gate to Source Leakage Current Drain to Source On-state Resistance Conditions Min Typ Max Unit VGS=0V, ID=0.25mA 50 – – V VDS=VGS, ID=0.25mA 0.5 0.9 2 V IDSS VDS=50V, VGS=0V – – 1 μA IGSS VGS=10V, VDS=0V – – ±10 μA RDS(ON) VGS=4.5V, ID=15A 12 17 30 mΩ Min Typ Max Unit – 1316 – – 97 – MOSFET Dynamic Characteristics Parameters Symbol Conditions Input Capacitance Ciss Output Capacitance Coss Reverse Transfer Capacitance Crss – 85 – Gate to Source Charge Qgs – 3.2 – Gate to Drain Charge (Miller Charger) Qgd – 5.7 – Total Gate Charge Qg – 15.2 – Gate Resistance Rg – 0.85 – APR3415 Document number: DS36738 Rev. 7 - 2 VGS=0V, VDS=25V, f=1MHz VGS=0V to 10V, VDD=25V, ID=15A – 5 of 13 www.diodes.com pF nC Ω June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Performance Characteristics Startup Voltage vs. Temperature UVLO vs. Temperature 3.5 3.50 Startup Voltage (V) 3.0 UVLO (V) 3.00 2.75 2.5 2.0 2.50 1.5 2.25 2.00 -40 -20 0 20 40 60 80 100 120 1.0 -40 140 -20 0 20 Internal Trigger Voltage vs. Temperature 80 100 120 140 Internal Trigger Current vs. Temperature 5.4 80 5.3 70 Internal Trigger Current (mA) Internal Trigger Voltage (V) 60 Temperature ( C) Temperature ( C) 5.2 5.1 5.0 4.9 60 50 40 30 20 4.8 4.7 -40 40 o o 10 -20 0 20 40 60 80 100 120 0 -40 140 -20 0 20 40 60 80 100 120 140 o o Temperature ( C) Temperature ( C) Overshoot Voltage for Discharge vs. Temperature Overshoot Current for Discharge vs. Temperature 160 Overshoot Current for Discharge (mA) 6.0 Overshoot Voltage for Discharge (V) NEW PRODUCT 3.25 5.8 5.6 5.4 5.2 140 120 100 80 60 40 20 5.0 -40 -20 0 20 40 60 80 100 120 0 -40 140 Document number: DS36738 Rev. 7 - 2 0 20 40 60 80 100 120 140 Temperature ( C) Temperature ( C) APR3415 -20 o o 6 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Performance Characteristics (Cont.) Gate Turn Off Threshold vs. Temperature Kqs (See Note 7) vs. Temperature 0.7 0 0.5 Kqs (mA*s) Gate Turn Off Threshold (mV) -10 -20 0.4 0.3 0.2 -30 0.1 -40 -40 -20 0 20 40 60 80 100 120 0.0 -40 140 -20 0 20 o 60 80 100 120 140 Temperature ( C) Operating Current vs. Temperature Drain to Source On-state Resistance vs. Temperature 50 Drain to Source On-state Resistance (m) 140 120 100 80 60 40 20 0 -40 40 o Temperature ( C) Operating Current (A) NEW PRODUCT 0.6 -20 0 20 40 60 80 100 120 35 30 25 20 15 10 5 -20 0 20 40 60 80 100 120 140 o Temperature ( C) Temperature ( C) Document number: DS36738 Rev. 7 - 2 40 0 -40 140 o APR3415 45 7 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Output Voltage Detect Function Description tOSC tDIS tDIS tDIS tDIS tDIS tDIS tOSC VDET VOVP VDIS VDIS NEW PRODUCT VTRIGGER VCC VTRIGGER VON UVLO IOVP IVCC VOFF tOVP_LAST IDIS Figure 1. Typical Waveforms of APR3415 When VCC is beyond power-on voltage (VON), the APR3415 starts up. The VDET pin asserts a periodical pulse and the oscillation period is t OSC. When VCC is beyond the trigger voltage (VTRIGGER), the periodical pulse at VDET pin is discontinued. When VCC is beyond the discharge voltage (VDIS), the discharge circuit will be enabled, and a 3mA current (IDIS) will flow into VCC pin. When VCC is higher than the overshoot voltage (VOVP), the APR3415 will enable a discharge circuit, the discharge current (IOVP) will last tOVP_LAST time. After the tOVP_LAST time, APR3415 will stop the discharge current and detect VCC voltage again. If VCC is still higher than VOVP, the tOVP_LAST time discharge current will be enabled again. Once the OVP discharge current is asserted, the periodical pulse at VDET pin will be disabled. When the VCC falls below the power-off voltage (VOFF), the APR3415 will shut down. Operation Description MOSFET Driver The operation of the SR is described with timing diagram shown in Figure 2. APR3415 monitors the MOSFET drain-source voltage. When the drain voltage is lower than the turn-on threshold voltage VTHON, the IC outputs a positive drive voltage after a turn-on delay time (tDON). The MOSFET will turn on and the current will transfer from the body diode into the MOSFET’s channel. In the process of drain current decreasing linearly toward zero, the drain-source voltage rises synchronically. When it rises over the turn off threshold voltage VTHOFF, APR3415 pulls the drive signal down after a turn off delay (tDOFF). I,V VDET IS VTHON 0 t VTHOFF VDRISR 0.9VDRISR 0.9VDRISR 0.1VDRISR 0 tDON tRG tDOFF 0.1VDRISR t tFG Figure 2. Typical Waveforms of APR3415 APR3415 Document number: DS36738 Rev. 7 - 2 8 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Operation Description (Cont.) Minimum On Time When the controlled MOSFET gate is turned on, some ringing noise is generated. The minimum on-time timer blanks the VTHOFF comparator, keeping the controlled MOSFET on for at least the minimum on time. If V THOFF falls below the threshold before minimum on time expires, the MOSFET will keep on until the end of the minimum on time. NEW PRODUCT The minimum on time is in direct proportion to the (VDET-VCC)*tONP. When (VDET-VCC)*tONP=5V*5μs, the minimum on time is about 1.8μs. The Value and Meaning of AREF Resistor As to DCM operation Flyback converter, after secondary rectifier stops conduction the primary MOSFET Drain-to-source ringing waveform is resulted from the resonant of primary inductance and equivalent switch device output capacitance. This ringing waveform probably leads to Synchronous Rectifier error conduction. To avoid this fault happening, APR3415 has a special function design by means of volt-second product detecting. From the sensed voltage of VDET pin to see, the volt-second product of voltage above VCC at primary switch on time is much higher than the volt-second product of each cycle ringing voltage above VCC. Therefore, before every time Synchronous Rectifier turning on, APR3415 judges if the detected volt-second product of VDET voltage above VCC is higher than a threshold and then turn on synchronous Rectifier. The purpose of AREF resistor is to determine the volt-second product threshold. APR3415 has a parameter, Kqs, which converts RAREF value to voltsecond product. Area2 R AREF * Kqs In general, Area1 and Area3, the value of which should be test on system, depend on system design and always are fixed after system design frozen. As to BCD PSR design, the Area1 value changes with primary peak current value and Area3 value generally keeps constant at all of conditions. So the AREF resistor design should consider the worst case, the minimum primary peak current condition. Since of system design parameter distribution, Area1 and Area3 have moderate tolerance. So Area2 should be designed between the middle of Area1 and Area3 to keep enough design margin. Area3 R AREF * Kqs Area1 Area1=(VDET-VCC)*tONP Area3 VDET VCC Area2=Kqs*RAREF Figure 3. AREF Function SR Minimum Operating Voltage APR3415 sets a minimum SR operating voltage by comparing the difference between V DET and output voltage (VCC). The value of VDET–VCC must be higher than its internal reference, then APR3415 will begin to integrate the area of (VDET–VCC)*tONP. If not, the area integrating will not begin and the SR driver will be disabled. SR Turning off Timing Impact on PSR CV Sampling As to synchronous rectification on Flyback power system, SR MOSFET need to turn off in advance of secondary side current decreasing to zero to avoid current flowing reversely. When SR turns off in advance, the secondary current will flow through the body diode. The SR turning off time is determined by the VTHOFF at a fixed system. When VTHOFF is more close to zero, the SR turning on time gets longer and body diode conduction time gets shorter. Since of the different voltage drop between SR MOSFET and body diode, the PSR feedback signal VFB appears a voltage jump at the time of SR MOSFET turning off. If the PSR CV sampling time tSAMPLE is close to even behind this voltage jump time, there will be system unstable operation issue or the lower output voltage issue. APR3415 Document number: DS36738 Rev. 7 - 2 9 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Operation Description (Cont.) To ensure stable operating of system, it must be met: tBODYDIODE<tONS*(1- tSAMPLE) tSAMPLE SR Turnoff, Bodydiode operating SR Operating NEW PRODUCT tBODYDIODE VFB tONS Figure 4. SR Turning off Timing Impact on PSR CV Sampling Recommended Application Circuit Parameters The two resistors R23 and R24 are used to pass ESD test. The value of R23 and R24 should be over 20Ω and below 47Ω respectively because of the undershoot performance. The package of R23 and R24 should be at least 0805 and there isn’t any trace under these two resistors. CAREF is suggested to parallel with AREF resistor to keep the volt-second product threshold stable. And the recommended value of CAREF is 100nF. The recommended value of C24 is 100nF. Ordering Information APR3415 X XX - XX Product Name Package Temperature Range SO-8 -40 to +85C APR3415 Document number: DS36738 Rev. 7 - 2 Package Packing RoHS/Green M : SO-8 TR : Tape & Reel G1 : Green Part Number APR3415MTR-G1 10 of 13 www.diodes.com Marking ID 3415M-G1 Packing 4000/Tape & Reel June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Marking Information 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. 3415M -G1 YWWAXX - 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 0.100(0. 004) 0.300(0. 012) R0.150(0.006) NEW PRODUCT (Top View) 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. APR3415 Document number: DS36738 Rev. 7 - 2 11 of 13 www.diodes.com June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 Suggested Pad Layout (1) Package Type: SO-8 NEW PRODUCT Grid placement courtyard G Z Y E Dimensions Value Z (mm)/(inch) 6.900/0.272 APR3415 Document number: DS36738 Rev. 7 - 2 G (mm)/(inch) 3.900/0.154 X X (mm)/(inch) 0.650/0.026 12 of 13 www.diodes.com Y (mm)/(inch) 1.500/0.059 E (mm)/(inch) 1.270/0.050 June 2015 © Diodes Incorporated A Product Line of Diodes Incorporated APR3415 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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