New Product Si7456DDP Vishay Siliconix N-Channel 100 V (D-S) MOSFET FEATURES PRODUCT SUMMARY ID (A)a VDS (V) RDS(on) () Max. 0.023 at VGS = 10 V 27.8 100 0.024 at VGS = 7.5 V 27.2 0.031 at VGS = 4.5 V 24 Qg (Typ.) 9.7 nC APPLICATIONS PowerPAK® SO-8 S 6.15 mm • DC/DC Primary Side Switch • Telecom/Server 48 V, Full/Half-Bridge DC/DC • Industrial • Synchronous Rectification 5.15 mm 1 S 2 S 3 • TrenchFET® Power MOSFET • 100 % Rg and UIS Tested • Material categorization: For definitions of compliance please see www.vishay.com/doc?99912 G 4 D 8 D G D 7 D 6 D 5 Bottom View S N-Channel MOSFET Ordering Information: Si7456DDP-T1-GE3 (Lead (Pb)-free and Halogen-free) ABSOLUTE MAXIMUM RATINGS (TA = 25 °C, unless otherwise noted) Parameter Drain-Source Voltage Gate-Source Voltage Symbol VDS VGS TC = 25 °C TC = 70 °C TA = 25 °C TA = 70 °C Continuous Drain Current (TJ = 150 °C) Limit 100 ± 20 ID TC = 25 °C TA = 25 °C IS Single Pulse Avalanche Current Single Pulse Avalanche Energy L =0.1 mH IAS EAS Maximum Power Dissipation TC = 25 °C TC = 70 °C TA = 25 °C TA = 70 °C PD Continuous Source-Drain Diode Current Operating Junction and Storage Temperature Range Soldering Recommendations (Peak Temperature) d, e TJ, Tstg V 27.8 22.2 IDM Pulsed Drain Current (t = 300 µs) Unit 10.4b, c 8.2b, c 70 25 A 4.5b, c 15 11.2 35.7 22.8 mJ 5b, c 3.2b, c - 55 to 150 260 W °C THERMAL RESISTANCE RATINGS Parameter Symbol Typical Maximum Unit RthJA t 10 s 20 25 Maximum Junction-to-Ambientb, f °C/W RthJC Steady State Maximum Junction-to-Case (Drain) 2.9 3.5 Notes: a. Based on TC = 25 °C. b. Surface mounted on 1" x 1" FR4 board. c. t = 10 s. d. See solder profile (www.vishay.com/doc?73257). The PowerPAK SO-8 is a leadless package. The end of the lead terminal is exposed copper (not plated) as a result of the singulation process in manufacturing. A solder fillet at the exposed copper tip cannot be guaranteed and is not required to ensure adequate bottom side solder interconnection. e. Rework conditions: manual soldering with a soldering iron is not recommended for leadless components. f. Maximum under steady state conditions is 70 °C/W. Document Number: 67869 S12-1261-Rev. A, 21-May-12 For technical questions, contact: [email protected] www.vishay.com 1 This document is subject to change without notice. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 New Product Si7456DDP Vishay Siliconix SPECIFICATIONS (TJ = 25 °C, unless otherwise noted) Parameter Symbol Test Conditions Min. VDS VGS = 0 V, ID = 250 µA 100 Typ. Max. Unit Static Drain-Source Breakdown Voltage VDS/TJ VDS Temperature Coefficient VGS(th)/TJ Gate-Source Threshold Voltage VGS(th) VDS = VGS, ID = 250 µA IGSS Gate-Source Leakage Zero Gate Voltage Drain Current IDSS On-State Drain Currenta ID(on) Drain-Source On-State Resistancea RDS(on) Forward Transconductancea gfs 67 ID = 250 µA VGS(th) Temperature Coefficient V mV/°C -5 2.8 V VDS = 0 V, VGS = ± 20 V ± 100 nA VDS = 100 V, VGS = 0 V 1 VDS = 100 V, VGS = 0 V, TJ = 55 °C 10 VDS 5 V, VGS = 10 V 1.5 30 µA A VGS = 10 V, ID = 10 A 0.017 0.023 VGS = 7.5 V, ID = 9 A 0.018 0.024 VGS = 4.5 V, ID = 8 A 0.022 0.031 VDS = 10 V, ID = 10 A 26 S Dynamicb Input Capacitance Ciss Output Capacitance Coss Reverse Transfer Capacitance Crss Total Gate Charge Qg Qgs Gate-Source Charge 900 VDS = 50 V, VGS = 0 V, f = 1 MHz 31 VDS = 50 V, VGS = 10 V, ID = 10 A 19.6 VDS = 50 V, VGS = 7.5 V, ID = 10 A 15 23 9.7 15 2.8 26.2 40 0.85 1.7 13 26 14 28 19 38 Qgd Output Charge Qoss VDS = 50 V, VGS = 0 V Rg f = 1 MHz tr Rise Time td(off) Turn-Off Delay Time Fall Time Turn-On Delay Time 10 20 td(on) 11 22 td(off) Turn-Off Delay Time VDD = 50 V, RL = 5 ID 10 A, VGEN = 7.5 V, Rg = 1 VDD = 50 V, RL = 5 ID 10 A, VGEN = 10 V, Rg = 1 tf Fall Time 0.2 tf tr Rise Time nC 4.3 td(on) Turn-On Delay Time 29.5 VDS = 50 V, VGS = 4.5 V, ID = 10 A Gate-Drain Charge Gate Resistance pF 340 10 20 20 40 9 18 ns Drain-Source Body Diode Characteristics Continuous Source-Drain Diode Current Pulse Diode Forward Currenta IS TC = 25 °C 25 ISM VSD Body Diode Voltage Body Diode Reverse Recovery Time trr Body Diode Reverse Recovery Charge Qrr Reverse Recovery Fall Time ta Reverse Recovery Rise Time tb 70 IS = 4 A IF = 5 A, dI/dt = 100 A/µs, TJ = 25 °C A 0.77 1.1 V 34 65 ns 34 65 nC 20 14 ns Notes: a. Pulse test; pulse width 300 µs, duty cycle 2 %. b. Guaranteed by design, not subject to production testing. Stresses beyond 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 in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. www.vishay.com 2 For technical questions, contact: [email protected] Document Number: 67869 S12-1261-Rev. A, 21-May-12 This document is subject to change without notice. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 New Product Si7456DDP Vishay Siliconix TYPICAL CHARACTERISTICS (25 °C, unless otherwise noted) 70 50 VGS = 10 V thru 5 V 40 ID - Drain Current (A) ID - Drain Current (A) 56 42 VGS = 4 V 28 14 30 TC = 25 °C 20 10 TC = 125 °C VGS = 3 V TC = - 55 °C 0 0 0 1 2 3 4 VDS - Drain-to-Source Voltage (V) 5 0.0 1.5 4.5 6.0 7.5 Transfer Characteristics 0.05 1500 0.04 1200 C - Capacitance (pF) RDS(on) - On-Resistance (Ω) Output Characteristics 0.03 VGS = 4.5 V VGS = 7.5 V 0.02 3.0 VGS - Gate-to-Source Voltage (V) VGS = 10 V Ciss 900 Coss 600 300 0.01 Crss 0 0.00 0 10 20 30 ID - Drain Current (A) 40 0 50 5 10 15 20 25 VDS - Drain-to-Source Voltage (V) On-Resistance vs. Drain Current and Gate Voltage Capacitance 10 2.0 RDS(on) - On-Resistance (Normalized) 8 VDS = 50 V 6 VDS = 25 V VDS = 75 V 4 2 0 0 4 VGS = 10 V ID = 15 A ID = 10 A VGS - Gate-to-Source Voltage (V) 30 9 13 18 Qg - Total Gate Charge (nC) Gate Charge Document Number: 67869 S12-1261-Rev. A, 21-May-12 22 1.7 1.4 VGS = 4.5 V 1.1 0.8 0.5 - 50 - 25 0 25 50 75 100 125 150 TJ - Junction Temperature (°C) On-Resistance vs. Junction Temperature For technical questions, contact: [email protected] www.vishay.com 3 This document is subject to change without notice. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 New Product Si7456DDP Vishay Siliconix TYPICAL CHARACTERISTICS (25 °C, unless otherwise noted) 100 0.15 ID = 15 A 0.12 TJ = 150 °C RDS(on) - On-Resistance (Ω) IS - Source Current (A) 10 TJ = 25 °C 1 0.1 0.01 0.09 0.06 TJ = 125 °C 0.03 TJ = 25 °C 0.001 0.0 0.2 0.4 0.6 0.8 1.0 VSD - Source-to-Drain Voltage (V) 0.00 1.2 0 0.5 200 0.2 160 - 0.1 ID = 5 mA - 0.4 ID = 250 μA - 0.7 - 1.0 - 50 - 25 0 25 50 75 10 On-Resistance vs. Gate-to-Source Voltage Power (W) VGS(th) - Variance (V) Source-Drain Diode Forward Voltage 2 4 6 8 VGS - Gate-to-Source Voltage (V) 120 80 40 100 125 150 0 0.001 TJ - Temperature (°C) 0.01 0.1 Time (s) 1 Threshold Voltage Single Pulse Power, Junction-to-Ambient 10 100 IDM Limited ID - Drain Current (A) 10 1 ms ID Limited 1 10 ms Limited by RDS(on)* 100 ms 0.1 1s TA = 25 °C Single Pulse 0.01 0.01 10 s DC BVDSS Limited 0.1 1 10 VDS - Drain-to-Source Voltage (V) * VGS > minimum VGS at which RDS(on) is specified 100 Safe Operating Area, Junction-to-Ambient www.vishay.com 4 For technical questions, contact: [email protected] Document Number: 67869 S12-1261-Rev. A, 21-May-12 This document is subject to change without notice. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 New Product Si7456DDP Vishay Siliconix TYPICAL CHARACTERISTICS (25 °C, unless otherwise noted) 30 I D - Drain Current (A) 24 18 12 6 0 0 25 50 75 100 125 T C - Case Temperature (°C) 150 45 2.5 36 2.0 27 1.5 Power (W) Power (W) Current Derating* 18 9 1.0 0.5 0 0.0 0 25 50 75 100 T C - Case Temperature (°C) Power, Junction-to-Case 125 150 0 25 50 75 100 125 150 TA - Ambient Temperature (°C) Power, Junction-to-Ambient * The power dissipation PD is based on TJ(max.) = 150 °C, using junction-to-case thermal resistance, and is more useful in settling the upper dissipation limit for cases where additional heatsinking is used. It is used to determine the current rating, when this rating falls below the package limit. Document Number: 67869 S12-1261-Rev. A, 21-May-12 For technical questions, contact: [email protected] www.vishay.com 5 This document is subject to change without notice. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 New Product Si7456DDP Vishay Siliconix TYPICAL CHARACTERISTICS (25 °C, unless otherwise noted) 1 Normalized Effective Transient Thermal Impedance Duty Cycle = 0.5 0.2 Notes: 0.1 0.1 PDM 0.05 t1 t2 1. Duty Cycle, D = 2. Per Unit Base = R thJA = 70 °C/W 0.02 3. T JM - TA = PDMZthJA(t) 4. Surface Mounted Single Pulse 0.01 0.0001 t1 t2 0.001 0.01 0.1 1 Square Wave Pulse Duration (s) 10 100 1000 Normalized Thermal Transient Impedance, Junction-to-Ambient 1 Normalized Effective Transient Thermal Impedance Duty Cycle = 0.5 0.2 0.1 0.1 0.01 0.0001 0.05 0.02 Single Pulse 0.001 0.01 0.1 Square Wave Pulse Duration (s) 1 10 Normalized Thermal Transient Impedance, Junction-to-Case Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Technology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and reliability data, see www.vishay.com/ppg?67869. www.vishay.com 6 For technical questions, contact: [email protected] Document Number: 67869 S12-1261-Rev. A, 21-May-12 This document is subject to change without notice. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Package Information Vishay Siliconix PowerPAK® SO-8, (SINGLE/DUAL) L H E2 K E4 D 3 4 θ 4 b 3 2 D5 e 2 D1 D 2 1 D2 Z 0.150 ± 0.008 M 1 D4 θ W L1 E3 θ A1 Backside View of Single Pad H K E2 E4 L 1 D1 D5 2 3 D2 4 Notes 1. Inch will govern. 2 Dimensions exclusive of mold gate burrs. 3. Dimensions exclusive of mold flash and cutting burrs. b D2 Detail Z K1 2 E1 E D3(2x) D4 c A θ E3 Backside View of Dual Pad MILLIMETERS INCHES DIM. MIN. NOM. MAX. MIN. NOM. A 0.97 1.04 1.12 0.038 0.041 MAX. 0.044 A1 0.00 - 0.05 0.000 - 0.002 b 0.33 0.41 0.51 0.013 0.016 0.020 c 0.23 0.28 0.33 0.009 0.011 0.013 D 5.05 5.15 5.26 0.199 0.203 0.207 D1 4.80 4.90 5.00 0.189 0.193 0.197 D2 3.56 3.76 3.91 0.140 0.148 0.154 D3 1.32 1.50 1.68 0.052 0.059 0.066 D4 0.57 TYP. D5 3.98 TYP. 0.0225 TYP. 0.157 TYP. E 6.05 6.15 6.25 0.238 0.242 0.246 E1 5.79 5.89 5.99 0.228 0.232 0.236 E2 3.48 3.66 3.84 0.137 0.144 0.151 E3 3.68 3.78 3.91 0.145 0.149 0.154 0.75 TYP. E4 0.030 TYP. e 1.27 BSC 0.050 BSC K 1.27 TYP. 0.050 TYP. K1 0.56 - - 0.022 - - H 0.51 0.61 0.71 0.020 0.024 0.028 L 0.51 0.61 0.71 0.020 0.024 0.028 L1 0.06 0.13 0.20 0.002 0.005 0.008 θ 0° - 12° 0° - 12° W 0.15 0.25 0.36 0.006 0.010 0.014 M 0.125 TYP. 0.005 TYP. ECN: T10-0055-Rev. J, 15-Feb-10 DWG: 5881 Document Number: 71655 Revison: 15-Feb-10 www.vishay.com 1 AN821 Vishay Siliconix PowerPAK® SO-8 Mounting and Thermal Considerations Wharton McDaniel MOSFETs for switching applications are now available with die on resistances around 1 mΩ and with the capability to handle 85 A. While these die capabilities represent a major advance over what was available just a few years ago, it is important for power MOSFET packaging technology to keep pace. It should be obvious that degradation of a high performance die by the package is undesirable. PowerPAK is a new package technology that addresses these issues. In this application note, PowerPAK’s construction is described. Following this mounting information is presented including land patterns and soldering profiles for maximum reliability. Finally, thermal and electrical performance is discussed. THE PowerPAK PACKAGE The PowerPAK package was developed around the SO-8 package (Figure 1). The PowerPAK SO-8 utilizes the same footprint and the same pin-outs as the standard SO-8. This allows PowerPAK to be substituted directly for a standard SO-8 package. Being a leadless package, PowerPAK SO-8 utilizes the entire SO-8 footprint, freeing space normally occupied by the leads, and thus allowing it to hold a larger die than a standard SO-8. In fact, this larger die is slightly larger than a full sized DPAK die. The bottom of the die attach pad is exposed for the purpose of providing a direct, low resistance thermal path to the substrate the device is mounted on. Finally, the package height is lower than the standard SO-8, making it an excellent choice for applications with space constraints. PowerPAK SO-8 SINGLE MOUNTING The PowerPAK single is simple to use. The pin arrangement (drain, source, gate pins) and the pin dimensions are the same as standard SO-8 devices (see Figure 2). Therefore, the PowerPAK connection pads match directly to those of the SO-8. The only difference is the extended drain connection area. To take immediate advantage of the PowerPAK SO-8 single devices, they can be mounted to existing SO-8 land patterns. Standard SO-8 PowerPAK SO-8 Figure 2. The minimum land pattern recommended to take full advantage of the PowerPAK thermal performance see Application Note 826, Recommended Minimum Pad Patterns With Outline Drawing Access for Vishay Siliconix MOSFETs. Click on the PowerPAK SO-8 single in the index of this document. In this figure, the drain land pattern is given to make full contact to the drain pad on the PowerPAK package. This land pattern can be extended to the left, right, and top of the drawn pattern. This extension will serve to increase the heat dissipation by decreasing the thermal resistance from the foot of the PowerPAK to the PC board and therefore to the ambient. Note that increasing the drain land area beyond a certain point will yield little decrease in foot-to-board and foot-toambient thermal resistance. Under specific conditions of board configuration, copper weight and layer stack, experiments have found that more than about 0.25 to 0.5 in2 of additional copper (in addition to the drain land) will yield little improvement in thermal performance. Figure 1. PowerPAK 1212 Devices Document Number 71622 28-Feb-06 www.vishay.com 1 AN821 Vishay Siliconix PowerPAK SO-8 DUAL The pin arrangement (drain, source, gate pins) and the pin dimensions of the PowerPAK SO-8 dual are the same as standard SO-8 dual devices. Therefore, the PowerPAK device connection pads match directly to those of the SO-8. As in the single-channel package, the only exception is the extended drain connection area. Manufacturers can likewise take immediate advantage of the PowerPAK SO-8 dual devices by mounting them to existing SO-8 dual land patterns. For the lead (Pb)-free solder profile, see http:// www.vishay.com/doc?73257. To take the advantage of the dual PowerPAK SO-8’s thermal performance, the minimum recommended land pattern can be found in Application Note 826, Recommended Minimum Pad Patterns With Outline Drawing Access for Vishay Siliconix MOSFETs. Click on the PowerPAK 1212-8 dual in the index of this document. The gap between the two drain pads is 24 mils. This matches the spacing of the two drain pads on the PowerPAK SO-8 dual package. REFLOW SOLDERING Vishay Siliconix surface-mount packages meet solder reflow reliability requirements. Devices are subjected to solder reflow as a test preconditioning and are then reliability-tested using temperature cycle, bias humidity, HAST, or pressure pot. The solder reflow temperature profile used, and the temperatures and time duration, are shown in Figures 3 and 4. Ramp-Up Rate + 6 °C /Second Maximum Temperature at 155 ± 15 °C 120 Seconds Maximum Temperature Above 180 °C 70 - 180 Seconds Maximum Temperature 240 + 5/- 0 °C Time at Maximum Temperature 20 - 40 Seconds Ramp-Down Rate + 6 °C/Second Maximum Figure 3. Solder Reflow Temperature Profile 10 s (max) 210 - 220 °C 3 °C(max) 4 °C/s (max) 183 °C 140 - 170 °C 50 s (max) 3 °C(max) 60 s (min) Pre-Heating Zone Reflow Zone Maximum peak temperature at 240 °C is allowed. Figure 3. Solder Reflow Temperatures and Time Durations www.vishay.com 2 Document Number 71622 28-Feb-06 AN821 Vishay Siliconix THERMAL PERFORMANCE Introduction A basic measure of a device’s thermal performance is the junction-to-case thermal resistance, Rθjc, or the junction-to-foot thermal resistance, Rθjf. This parameter is measured for the device mounted to an infinite heat sink and is therefore a characterization of the device only, in other words, independent of the properties of the object to which the device is mounted. Table 1 shows a comparison of the DPAK, PowerPAK SO-8, and standard SO-8. The PowerPAK has thermal performance equivalent to the DPAK, while having an order of magnitude better thermal performance over the SO-8. TABLE 1. DPAK and PowerPAK SO-8 Equivalent Steady State Performance Thermal Resistance Rθjc DPAK PowerPAK SO-8 Standard SO-8 1.2 °C/W 1.0 °C/W 16 °C/W Thermal Performance on Standard SO-8 Pad Pattern Because of the common footprint, a PowerPAK SO-8 can be mounted on an existing standard SO-8 pad pattern. The question then arises as to the thermal performance of the PowerPAK device under these conditions. A characterization was made comparing a standard SO-8 and a PowerPAK device on a board with a trough cut out underneath the PowerPAK drain pad. This configuration restricted the heat flow to the SO-8 land pads. The results are shown in Figure 5. Because of the presence of the trough, this result suggests a minimum performance improvement of 10 °C/W by using a PowerPAK SO-8 in a standard SO-8 PC board mount. The only concern when mounting a PowerPAK on a standard SO-8 pad pattern is that there should be no traces running between the body of the MOSFET. Where the standard SO-8 body is spaced away from the pc board, allowing traces to run underneath, the PowerPAK sits directly on the pc board. Thermal Performance - Spreading Copper Designers may add additional copper, spreading copper, to the drain pad to aid in conducting heat from a device. It is helpful to have some information about the thermal performance for a given area of spreading copper. Figure 6 shows the thermal resistance of a PowerPAK SO-8 device mounted on a 2-in. 2-in., four-layer FR-4 PC board. The two internal layers and the backside layer are solid copper. The internal layers were chosen as solid copper to model the large power and ground planes common in many applications. The top layer was cut back to a smaller area and at each step junction-toambient thermal resistance measurements were taken. The results indicate that an area above 0.3 to 0.4 square inches of spreading copper gives no additional thermal performance improvement. A subsequent experiment was run where the copper on the back-side was reduced, first to 50 % in stripes to mimic circuit traces, and then totally removed. No significant effect was observed. Si4874DY vs. Si7446DP PPAK on a 4-Layer Board SO-8 Pattern, Trough Under Drain Rth vs. Spreading Copper (0 %, 50 %, 100 % Back Copper) 60 56 Impedance (C/watts) Impedance (C/watts) 50 40 Si4874DY 30 Si7446DP 20 51 46 100 % 41 10 0% 50 % 0 0.0001 0.01 1 100 10000 Pulse Duration (sec) Figure 5. PowerPAK SO-8 and Standard SO-0 Land Pad Thermal Path Document Number 71622 28-Feb-06 36 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 Figure 6. Spreading Copper Junction-to-Ambient Performance www.vishay.com 3 AN821 Vishay Siliconix SYSTEM AND ELECTRICAL IMPACT OF PowerPAK SO-8 In any design, one must take into account the change in MOSFET rDS(on) with temperature (Figure 7). On-Resistance vs. Junction Temperature r DS(on) - On-Resistance ( ) (Normalized) 1.8 1.6 VGS = 10 V ID = 23 A Suppose each device is dissipating 2.7 W. Using the junction-to-foot thermal resistance characteristics of the PowerPAK SO-8 and the standard SO-8, the die temperature is determined to be 107 °C for the PowerPAK (and for DPAK) and 148 °C for the standard SO-8. This is a 2 °C rise above the board temperature for the PowerPAK and a 43 °C rise for the standard SO-8. Referring to Figure 7, a 2 °C difference has minimal effect on rDS(on) whereas a 43C difference has a significant effect on rDS(on). Minimizing the thermal rise above the board temperature by using PowerPAK has not only eased the thermal design but it has allowed the device to run cooler, keep rDS(on) low, and permits the device to handle more current than the same MOSFET die in the standard SO-8 package. 1.4 1.2 1.0 0.8 0.6 - 50 - 25 0 25 50 75 100 125 150 TJ - Junction Temperature (°C) Figure 7. MOSFET rDS(on) vs. Temperature A MOSFET generates internal heat due to the current passing through the channel. This self-heating raises the junction temperature of the device above that of the PC board to which it is mounted, causing increased power dissipation in the device. A major source of this problem lies in the large values of the junction-to-foot thermal resistance of the SO-8 package. PowerPAK SO-8 minimizes the junction-to-board thermal resistance to where the MOSFET die temperature is very close to the temperature of the PC board. Consider two devices mounted on a PC board heated to 105 °C by other components on the board (Figure 8). PowerPAK SO-8 Standard SO-8 107 °C 0.8 °C/W 148 °C CONCLUSIONS PowerPAK SO-8 has been shown to have the same thermal performance as the DPAK package while having the same footprint as the standard SO-8 package. The PowerPAK SO-8 can hold larger die approximately equal in size to the maximum that the DPAK can accommodate implying no sacrifice in performance because of package limitations. Recommended PowerPAK SO-8 land patterns are provided to aid in PC board layout for designs using this new package. Thermal considerations have indicated that significant advantages can be gained by using PowerPAK SO-8 devices in designs where the PC board was laid out for the standard SO-8. Applications experimental data gave thermal performance data showing minimum and typical thermal performance in a SO-8 environment, plus information on the optimum thermal performance obtainable including spreading copper. This further emphasized the DPAK equivalency. PowerPAK SO-8 therefore has the desired small size characteristics of the SO-8 combined with the attractive thermal characteristics of the DPAK package. 16 C/W PC Board at 105 °C Figure 8. Temperature of Devices on a PC Board www.vishay.com 4 Document Number 71622 28-Feb-06 Application Note 826 Vishay Siliconix RECOMMENDED MINIMUM PADS FOR PowerPAK® SO-8 Single 0.260 (6.61) 0.150 (3.81) 0.050 0.174 (4.42) 0.154 (1.27) 0.026 (0.66) (3.91) 0.024 (0.61) 0.050 0.032 0.040 (1.27) (0.82) (1.02) Recommended Minimum Pads Dimensions in Inches/(mm) Return to Index Return to Index APPLICATION NOTE Document Number: 72599 Revision: 21-Jan-08 www.vishay.com 15 Legal Disclaimer Notice www.vishay.com Vishay Disclaimer ALL PRODUCT, PRODUCT SPECIFICATIONS AND DATA ARE SUBJECT TO CHANGE WITHOUT NOTICE TO IMPROVE RELIABILITY, FUNCTION OR DESIGN OR OTHERWISE. Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf (collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained in any datasheet or in any other disclosure relating to any product. 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Material Category Policy Vishay Intertechnology, Inc. hereby certifies that all its products that are identified as RoHS-Compliant fulfill the definitions and restrictions defined under Directive 2011/65/EU of The European Parliament and of the Council of June 8, 2011 on the restriction of the use of certain hazardous substances in electrical and electronic equipment (EEE) - recast, unless otherwise specified as non-compliant. Please note that some Vishay documentation may still make reference to RoHS Directive 2002/95/EC. We confirm that all the products identified as being compliant to Directive 2002/95/EC conform to Directive 2011/65/EU. Revision: 12-Mar-12 1 Document Number: 91000