ZXGD3104N8 SYNCHRONOUS MOSFET CONTROLLER IN SO8 Description Features The ZXGD3104 is intended to drive MOSFETs configured as ideal diode replacements. The device is comprised of a differential amplifier detector stage and high current driver. The detector monitors the reverse voltage of the MOSFET, such that if the body diode conduction occurs, a positive voltage is applied to the MOSFET’s Gate Pin. 5-25V VCC Range Operating up to 250kHz Suitable for Discontinuous Conduction Mode (DCM), Critical Conduction Mode (CrCM), and Continuous Conduction Mode (CCM) Operation Turn-Off Propagation Delay 15ns and Turn-Off Time 20ns Proportional Gate Drive Control Detector Threshold Voltage -10mV Standby Current 5mA Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) Qualified to AEC-Q101 Standards for High Reliability Once the positive voltage is applied to the Gate, the MOSFET switches on. The detector’s output voltage is then proportional to the MOSFET Drain-Source voltage, and this is applied to the Gate via the driver. This action provides a rapid MOSFET turn-off at zero Drain current. Applications Mechanical Data Flyback Converters in: ≥90W Laptop Adaptors Case: SO-8 Case material: Molded Plastic. “Green” Molding Compound. UL Flammability Rating 94V-0 Moisture Sensitivity: Level 1 per J-STD-020 Terminals: Matte Tin Finish – Solderable per MIL-STD-202, Method 208 Weight: 0.074 grams (Approximate) Typical Configuration SO-8 DNC DRAIN REF BIAS GATEL GND GATEH VCC Top View Pin-Out Ordering Information (Note 4) Product ZXGD3104N8TC Notes: Marking ZXGD3104 Reel Size (inches) 13 Tape Width (mm) 12 Quantity per Reel 2,500 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 chlorine1500ppm total Br + Cl) and <1000ppm antimony compounds. 4. For packaging details, go to our website at http://www.diodes.com/products/packages.html. Marking Information ZXGD 3104 YY WW ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 ZXGD 3104 YY WW = Product Type Marking Code, Line 1 = Product Type Marking Code, Line 2 = Year (ex: 11 = 2011) = Week (01 - 53) 1 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Functional Block Diagram Pin Number Name 1 DNC Do Not Connect Leave pin floating. 2 REF Reference This pin is connected to VCC via resistor, RREF. Select RREF to source 2.16mA into this pin. Refer to Table 1 in Application Information section. 3 GATEL Gate Turn-Off This pin sinks current, ISINK, from the synchronous MOSFET Gate. 4 GATEH Gate Turn-On This pin sources current, ISOURCE, to the synchronous MOSFET Gate. 5 VCC Power Supply This is the supply pin. It is recommended to decouple this point to Ground closely with a ceramic capacitor. 6 GND Ground This is the ground reference point. Connect to the synchronous MOSFET Source terminal. 7 BIAS Bias This pin is connected to VCC via resistor, RBIAS. Select RBIAS to Source 3mA into this pin. Refer to Table 1 in Application Information section. 8 DRAIN ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 Description and Function Drain Connection This pin connects directly to the synchronous MOSFET Drain terminal. 2 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Maximum Ratings (@TA = +25°C, unless otherwise specified.) Characteristic Supply Voltage, Relative to GND Drain Pin Voltage Gate Output Voltage Gate Driver Peak Source Current Gate Driver Peak Sink Current Reference Voltage Reference Current Bias Voltage Bias Current Symbol VCC VD VG ISOURCE ISINK VREF IREF VBIAS IBIAS Value 25 -3 to 180 -3 to VCC +3 2.5 7 VCC 25 VCC 100 Unit V V V A A V mA V mA Value 490 Unit Thermal Characteristics (@TA = +25°C, unless otherwise specified.) Characteristic Symbol (Note 5) Power Dissipation Linear Derating Factor 3.92 655 (Note 6) PD (Note 7) Thermal Resistance, Junction to Ambient Thermal Resistance, Junction to Lead Operating Temperature Range Storage Temperature Range Notes: 720 mW mW/°C 5.76 785 (Note 8) (Note 5) (Note 6) (Note 7) (Note 8) (Note 9) 5.24 6.28 RθJA RθJL TJ TSTG 255 191 173 159 135 -40 to +150 -55 to +150 °C/W °C/W °C 5. For a device surface mounted on minimum recommended pad layout FR4 PCB with high coverage of single sided 1oz copper, in still air conditions; the device is measured when operating in a steady-state condition. 6. Same as Note (5), except Pin 5 (VCC) and Pin 6 (GND) are both connected to separate 5mm x 5mm 1oz copper heatsinks. 7. Same as Note (6), except both heatsinks are 10mm x 10mm. 8. Same as Note (6), except both heatsinks are 15mm x 15mm. 9. Thermal resistance from junction to solder-point at the end of each lead on Pin 5 (VCC) and Pin 6 (GND). ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 3 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Max Power Dissipation (W) Thermal Derating Curve 0.8 15mm x 15mm 0.7 10mm x 10mm 0.6 0.5 5mm x 5mm 0.4 Minimum Layout 0.3 0.2 0.1 0.0 0 20 40 60 80 100 120 140 160 Junction Temperature (°C) Derating Curve ESD Rating Characteristic Value ESD for Human Body Model 2,000 ESD for Machine Model ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 Unit V 300 4 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Electrical Characteristics (@TA = +25°C, unless otherwise specified.) VCC = 19V; RBIAS = 6.3kΩ; RREF = 8.5kΩ Characteristic Input and Supply Quiescent Current Gate Driver Turn-Off Threshold Voltage (Notes 10 & 11) (Notes 10 & 11) Gate Output Voltage (Notes 10 & 12) Symbol Min Typ Max Unit IQ — 5.16 — mA VD ≥ 0V VT VG(off) -16 0 12.5 17 -10 0.73 14 18 0 1.0 VCC VCC mV VG = 1V VD ≥ 1V VD = -50mV VD = -100mV 175 11 335 530 35 250 15 480 760 50 325 20 625 990 65 VG Switching Performance for QG(tot) = 124nC (Note 13) Turn-On Propagation Delay td(rise) Turn-Off Propagation Delay td(fall) Gate Rise Time tr Gate Fall Time tf Notes: V Test Condition — ns Refer to Switching From 10% of VG to 10V Waveforms in Fig. 1 From 10% to 90% of VG Continuous Conduction Mode 10. GATEH connected to GATEL 11. RH = 100kΩ, RL = O/C 12. RL = 100kΩ, RH = O/C 13. Refer to test circuit below. Test Circuit ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 5 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Typical Electrical Characteristics (@TA = +25°C, unless otherwise specified.) ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 6 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Typical Electrical Characteristics (Continued) (@TA = +25°C, unless otherwise specified.) ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 7 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Application Information Descriptions of the Normal Operation The operation of the controller is described step-by-step with reference to the timing diagram in Figure 1. 1. The controller monitors the MOSFET Drain-Source voltage. 2. When the MOSFET body diode is forced to conduct, due to transformer action, there is approximately -0.8V on the Drain Pin. 3. The detector outputs a positive voltage with respect to Ground, this voltage is then fed to the MOSFET driver stage and current is sourced out of the Gate Pin. 4. The controller goes into proportional gate drive control – the Gate output voltage is proportional to the on-resistance-induced Drain-Source voltage drop across the MOSFET. Proportional gate drive ensures that MOSFET conducts for majority of the conduction cycle and minimizes body diode conduction time. 5. As the Drain current decays linearly toward zero, proportional gate drive control reduces the Gate voltage so the MOSFET can be turned off rapidly at zero current crossing. The Gate voltage is removed when the Drain-Source voltage crosses the detection threshold voltage to minimize reverse current flow. 6. At zero Drain current, the controller Gate output voltage is pulled low to VG(off) to ensure that the MOSFET is turned off. MOSFET Drain Voltage VD 1 VT Body Diode Conduction 2 3 90% MOSFET Gate Voltage 4 5 VG 90% 10% 6 10% VG(off) tf tr td(fall) td(rise) MOSFET Drain Current ID 0A Figure 1: Timing Diagram for a Critical Conduction Mode Flyback Converter ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 8 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Application Information (Continued) The purpose of the ZXGD3104 is to drive a MOSFET as a low VF Schottky diode replacement in offline power converters. When combined with a low RDS(ON) MOSFET, it can yield significant power efficiency improvement, while maintaining design simplicity and incurring minimal component count. Figure 2 shows the typical configuration of ZXGD3104 for synchronous rectification in a 19V output flyback adaptor. Figure 2: Example Connections in Flyback Power Supply ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 9 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Application Information (Cont.) Figure 3 shows operating waveforms for ZXGD3104 driving a MOSFET with Qg(TOT) = 124nC in a 19V output flyback converter operating in critical conduction mode. Typical waveforms Fig 3a: Critical Conduction Mode, Operating for MOSFET with Qg(TOT) = 124nC Fig 3b: Typical Switching Waveform Figure 3c: Close-Up of Typical Turn-Off Waveform ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 10 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 Application Information (Cont.) Design Considerations It is advisable to decouple the ZXGD3104 closely to VCC and ground due to the possibility of high peak gate currents with a 1μF X7R type ceramic capacitor C1 as shown in Figure 2. Also the Ground return loop should be as short as possible. To minimize parasitic inductance-induced premature turn-off of the synchronous controller, always keep the PCB track length between ZXGD3104’s Drain input and the MOSFET’s Drain to less than 10mm. Low internal inductance SMD MOSFET packages are also recommended for high switching frequency power conversion to minimize MOSFET body diode conduction loss. The Gate Pins should be as close to the MOSFET’s gate as possible. External gate resistors are optional. They can be inserted to control the rise and fall time which may help with EMI issues. The careful selection of external resistors RREF and RBIAS is important to the optimum device operation. Select a value for resistor RREF and RBIAS from Table 1 based on the desired VCC value. This provides the typical ZXGD3104’s detection threshold voltage of -10mV. Table 1: Recommended Resistor Values for Various Supply Voltages VCC 5V 10V 12V 15V 19V ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 RBIAS 1.6kΩ 3.3kΩ 3.9kΩ 5.1kΩ 6.3kΩ 11 of 13 www.diodes.com RREF 2kΩ 4.3kΩ 5.1kΩ 6.8kΩ 8.5kΩ November 2015 © Diodes Incorporated ZXGD3104N8 Package Outline Dimensions Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version. 0.254 SO-8 E1 E A1 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. SO-8 X Dimensions X Y C1 C2 Value (in mm) 0.60 1.55 5.4 1.27 C1 C2 Y Note: For high voltage applications, the appropriate industry sector guidelines should be considered with regards to creepage and clearance distances between device Terminals and PCB tracking. ZXGD3104N8 Document Number DS35546 Rev. 2 - 2 12 of 13 www.diodes.com November 2015 © Diodes Incorporated ZXGD3104N8 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). 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. 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