APR34150 SECONDARY SIDE SYNCHRONOUS RECTIFICATION SWITCHER Description Pin Assignments APR34150 is a secondary side Combo IC, which combines an NChannel MOSFET and a driver circuit designed for synchronous rectification (SR) in DCM operation. (Top View) NEW PRODUCT 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 AREF 3 6 GND VCC 4 5 GND The synchronous rectification can effectively reduce the secondary side rectifier power dissipation and provide high performance solution. By sensing MOSFET drain-to-source voltage, APR34150 can output ideal drive signal with less external components. It can provide high performance solution for 5V output voltage application. The APR34150 is available in SO-8 package. SO-8 Applications Features • Synchronous Rectification for DCM Operation Flyback • Eliminate Resonant Ring Interference • Fast Detector of Supply Voltages • Fewest External Components • • Adapters/Chargers for Cell/Cordless Phones, ADSL Modems, MP3 and Other Portable Apparatus Standby and Auxiliary Power Supplies 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 APR34150 R23 DRAIN GND DRAIN GND VDET VCC DRISR AREF RAREF APR34150 Document number: DS37985 Rev. 2 - 2 R24 C24 CAREF 1 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 NEW PRODUCT Pin Descriptions Pin Number Pin Name Function 1 DRISR Synchronous rectification MOSFET drive 2 VDET Synchronous rectification sense input, 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 OVP IAREF tONPDET AREF DRISR Counter 3 OSC 1 SRDRIVER 5, 6 DRAIN GND 7, 8 2 VDET APR34150 Document number: DS37985 Rev. 2 - 2 2 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 Absolute Maximum Ratings (Note 4) Symbol NEW PRODUCT VCC Parameter Supply Voltage Rating Unit -0.3 to 7.5 V VDET, VDRAIN Voltage at VDET, DRAIN Pin -2 to 50 V VAREF, VDRISR Voltage at AREF, DRISR Pin -0.3 to 6 V 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 Operating Junction Temperature TSTG Storage Temperature TLEAD Lead Temperature (Soldering, 10 sec) Notes: 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 APR34150 Document number: DS37985 Rev. 2 - 2 3 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 Electrical Characteristics Symbol (@TA = +25°C, VCC =5V, unless otherwise specified.) Parameter Conditions Min Typ Max Unit Supply Voltage ( VCC Pin ) ISTARTUP IOP NEW PRODUCT VSTARTUP – VOVP IOVP Startup Current VCC=VSTARTUP-0.1V – 100 150 μA Operating Current VDET pin floating VCC=VTRIGGER+20mV 40 100 150 μA Startup Voltage – – 3.1 – V UVLO – – 2.8 – V Overshoot Voltage for Discharge – 5.7 5.8 5.9 V Overshoot Current for Discharge VCC=VOVP+0.1V, VCC pin is connected to a 20Ω resistor 40 – 100 mA 1 V Synchronous Voltage Detect VTHON Gate Turn On Threshold – 0 – 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 ns tLEB_S Minimum On Time tLEB_L VDRISR_HIGH VS_MIN tOVP_LAST Kqs Notes: – 50 100 – 0.9 1.8 2.7 – – – 6.5 3.7 – – V μs Drive Output Voltage VCC=5V SR Minimum Operating Voltage (Note 6) – – – 4.5 V Added OVP Discharge Time – – 1.0 – ms (Note 7) (VDET-VCC)*tONP = 25Vµs 0.325 – 0.515 mA*μs 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. APR34150 Document number: DS37985 Rev. 2 - 2 4 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 Electrical Characteristics (@TA =+25°C, unless otherwise specified. Cont.) MOSFET Static Characteristics Parameters Drain to Source Breakdown Voltage NEW PRODUCT Gate Threshold Voltage Zero Gate Voltage Drain Current Gate to Source Leakage Current Drain to Source On-state Resistance Symbol Conditions Min Typ Max Unit VDSS(BR) VGS=0V, ID=0.25mA 50 – – V VGS(TH) 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 – – 85 – – 3.2 – – 5.7 – – 15.2 – – 0.85 – MOSFET Dynamic Characteristics Parameters Symbol Input Capacitance Ciss Output Capacitance Coss Reverse Transfer Capacitance Crss Gate to Source Charge Qgs Gate to Drain Charge (Miller Charger) Qgd Total Gate Charge Qg Gate Resistance Rg Conditions VGS=0V, VDS=25V, f=1MHz VGS=0V to 10V, VDD=25V, ID=15A – pF nC Ω Operation Description MOSFET Driver The operation of the SR is described with timing diagram shown in Figure 1. APR34150 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, APR34150 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 1. Typical Waveforms of APR34150 APR34150 Document number: DS37985 Rev. 2 - 2 5 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 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 VTHOFF falls below the threshold before minimum on time expires, the MOSFET will keep on until the end of the minimum on time. 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. NEW PRODUCT The Value and Meaning of AREF Resistor As to DCM operation Flyback converter, after secondary rectifier stop 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, APR34150 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, APR34150 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. APR34150 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 are always 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 conditions. So the AREF resistor design should consider the worst case, the minimum primary peak current condition. Since of system design parameter distribution, Areas1 and Area3 have moderate tolerance. So Aarea2 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 2. AREF Function SR Minimum Operating Voltage APR34150 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 APR34150 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. APR34150 Document number: DS37985 Rev. 2 - 2 6 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 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 3. 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 APR34150 X XX - XX Product Name Package Temperature Range SO-8 -40 to +85C Package Packing RoHS/Green M : SO-8 TR : Tape & Reel G1 : Green Part Number APR34150MTR-G1 Marking ID 34150M-G1 Packing 4000/Tape & Reel Marking Information (Top View) 34150 M-G1 YWWAXX - APR34150 Document number: DS37985 Rev. 2 - 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. 7 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 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) NEW PRODUCT 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 . APR34150 Document number: DS37985 Rev. 2 - 2 8 of 10 www.diodes.com October 2015 © Diodes Incorporated APR34150 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 APR34150 Document number: DS37985 Rev. 2 - 2 G (mm)/(inch) 3.900/0.154 X X (mm)/(inch) 0.650/0.026 9 of 10 www.diodes.com Y (mm)/(inch) 1.500/0.059 E (mm)/(inch) 1.270/0.050 October 2015 © Diodes Incorporated APR34150 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). NEW PRODUCT 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 APR34150 Document number: DS37985 Rev. 2 - 2 10 of 10 www.diodes.com October 2015 © Diodes Incorporated