NIS3001A Integrated Driver and MOSFET Power Chip for Synchronous Buck Controllers The NIS3001A is an integrated multi−chip solution for high power DC to DC synchronous buck converters. It contains two power MOSFETs that are controlled by an internal Driver. All three die are packaged in a power QFN package called PInPAK. The 10.5 by 10.5 mm PInPAK package increases power density and simplifies PCB layout. The device can be used in single or multi−phase applications. The NIS3001A implements the newest MOSFET technology. The control MOSFET is designed to provide improved switching performance and operates at a much lower temperature compared to discrete solutions. The synchronous MOSFET is designed to reduce conduction and switching losses at high frequencies. The integrated solution greatly reduces the parasitic inductance associated with conventional discrete buck converters and results in the highest power conversion efficiency. The power density of the NIS3001A is optimized based on MOSFET die size and PInPAK design. The PInPAK layout allows for direct routing into each power terminal. This results in a better thermal solution for the system. In addition its thermal resistance is 50% lower than BGAs. In summary, the NIS3001A has an improved efficiency, reliability and scalability for multi−phase synchronous buck converters. http://onsemi.com MARKING DIAGRAM A WL YY WW = Assembly Site = Wafer Lot = Year = Work Week PINOUT DIAGRAM 14 15 16 17 11 12 10 VS Analog Driver IC 18 19 1 2 3 4 21 7 5 Matched MOSFETs for Optimal Efficiency 10.5 mm x 10.5 mm PInPAK Package 31 A DC Output Current 7.0 to 14 V Input Voltage Range Internal Thermal Shutdown Operating Frequency Range up to 1,000 kHz 0.7 V to 5.1 V Output Voltage Range Nominal Duty Cycle 5 to 50% Hi Side Discrete FETs 13 20 Features • • • • • • • • NIS3001A AWLYYWW CASE 500 PInPAK 10.5x10.5 PLLP 9 8 6 (Bottom View) ORDERING INFORMATION Device Package Shipping† NIS3001AQPT1 PInPAK 1500/Tape & Reel †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification Brochure, BRD8011/D. VIN DRN Lo Side Discrete FETs PGND Figure 1. Semiconductor Components Industries, LLC, 2003 October, 2003 − Rev. 1 1 Publication Order Number: NIS3001A/D NIS3001A BST (17) (4) + − VIN (15, 16) (12, 13) Level Shifter + − VS TG 4.35 V Delay EN + − Non−Overlap Control (3) DRN (7−11, 14, 18) 4.0 V Delay Thermal Shutdown VS (1) CO (2, 19) GND BG (20, 21) PGND (5, 6) Figure 2. Block Diagram PIN FUNCTION DESCRIPTIONS Pad # Symbol 1 CO Description 2, 19 GND 3 EN Logic level enable input forces internal driver top gate and bottom gate low, and supply current to less than 10 A when EN is low. 4 VS Power supplied to the internal driver. A 1.0 F ceramic capacitor should be connected from this pin to PGND. Logic level control input produces complementary output states. Signal ground. 5, 6 PGND 7−11, 14, 18 DRN Power ground. High current return path for the lower internal. Switching Node, connected to output inductor (10). Switching Node, connected to the boost capacitor (14). All pins connected internally. 12, 13 VIN DC−DC converter input voltage. 15, 16 TG High Side Driver Output (Top Gate, this pin is used to monitor the gate). 17 BST Bootstrap supply voltage input. In conjunction with a Schottky diode to Vs, a 0.1 F to 1.0 F ceramic capacitor connected between BST and DRN (14). 20, 21 BG Low Side Driver Output (Bottom Gate, this pin is used to monitor the gate). http://onsemi.com 2 NIS3001A MAXIMUM RATINGS* Rating Operating Junction Temperature, TJ Output DC Current (Note 2) Value Unit 125 °C 31 A °C/W Package Thermal Resistance: Junction to Ambient, RJ−A (4 layer PCB with vias, no air flow) Junction to Ambient, RJ−A (4 layer PCB with vias, 200lfm air flow) Junction to PCB, RJ−PCB (4 layer PCB with vias) 26 13 8.0 Storage Temperature Range, TS ESD Susceptibility (Human Body Model) Lead Temperature Soldering: Reflow: (SMD styles only) (Note 1) JEDEC Moisture Sensitivity Level −65 to 150 °C 500 V 230 peak °C 3.0 MSL Pin Symbol Pin Name MAX MIN ISOURCE ISINK VS Driver Supply Voltage 6.3 V −0.3 V NA 4.0 A Peak (< 100 s) 250 mA DC BST Bootstrap Supply Voltage Input 25 V wrt/PGND 6.3 V wrt/DRN −0.3 V wrt/DRN NA 4.0 A Peak (< 100 s) 250 mA DC DRN Switching Node (Bootstrap Supply Return) 25 V −1.0 V DC −5.0 V for 100 ns −6.0 V for 20 ns 4.0 A Peak (< 100 s) 250 mA DC NA TG High Side Driver Output (Top Gate) 25 V wrt/PGND 6.3 V wrt/DRN −0.3 V wrt/DRN 4.0 A Peak (< 100 s) 250 mA DC 4.0 A Peak (< 100 s) 250 mA DC BG Low Side Driver Output (Bottom Gate) 6.3 V −0.3 V 4.0 A Peak (< 100 s) 250 mA DC 4.0 A Peak (< 100 s) 250 mA DC CO TG & BG Control Input 6.3 V −0.3 V 1.0 mA 1.0 mA EN Enable Input 6.3 V −0.3 V 1.0 mA 1.0 mA PGND Ground 0V 0V 4.0 A Peak (< 100 s) 250 mA DC NA VIN Input Supply Voltage 14 V − − − NOTE: All voltages are with respect to PGND except where noted. 1. 60 seconds maximum above 183°C. 2. Measured with heat sink attached to DUT, 200 Ifm, TA = 25°C and VOUT < 3.3 V, see Figures 21 and 22. *The maximum package power dissipation must be observed. http://onsemi.com 3 NIS3001A ELECTRICAL CHARACTERISTICS (Test conditions unless otherwise noted; VIN = 12 V, VS = VBST = VEN = 5 V, FSW = 500 kHz, VCO = 4 V) Characteristic Symbol Min Typ Max − − 0.85 2.67 − − Unit DC OPERATING SPECIFICATIONS Power Supply Power Loss VOUT = 1.5 V, IOUT = 4.5 A VOUT = 1.5 V, IOUT = 15 A PLOSS W VS Operating Current, (switching) IVS − 19 − mA VS Quiescent Current, Shutdown, VEN = 0 V IVS − 10 − A Bootstrap Operating Current, (switching) IBST − 7 10 mA Enable Input Bias Current IEN − 1 − A EN High Threshold, (Operating), VIN = open VEN 2.0 − − V EN Low Threshold, (Shutdown), VIN = open VEN − − 0.8 V Undervoltage Lockout, Turn on (VCO = VEN = 4.0 V, VIN = open) UVLO 4.0 4.25 4.48 V Hysteresis Undervoltage Lockout (VCO = VEN = 4.0 V, VIN = open) Vhyst − 275 − mV Undervoltage Lockout, Turn off (VCO = VEN = 4.0 V, VIN = open) UVLO 3.7 4.0 4.3 V CO Input Bias Current (VIN = open, VCO = 4 V ICO − 3.0 − nA CO High Threshold, VIN = open VCO 2.0 − − V CO Low Threshold, VIN = open VCO − − 0.8 V Overtemperature Trip Point − 170 − °C Hysteresis − 30 − °C EN Input Characteristics Undervoltage Lockout CO Input Characteristics Thermal Shutdown AC OPERATING SPECIFICATIONS High−Side Driver Propagation Delay Time, TG Going High (Nonoverlap time); 50% between BG (going low) and TG (going high) VBST − VDRN = 5.0 V tpdhTG − 45 − ns Propagation Delay Time, TG Going Low; 50% between CO (going low) and TG (going low) VBST − VDRN = 5.0 V tpdlTG − 60 − ns Propagation Delay Time, BG Going High (Nonoverlap time); 50% between DRN (going low) and BG (going high) tpdhBG − 43 − ns Propagation Delay Time, BG Going Low; 50% between CO (going high) and BG (going low) tpdlBG − 8.0 − ns RDS(on) − 8.1 − m RDS(on) − 4.7 − m POWER MOSFET ON CHARACTERISTICS High−Side Driver Static Drain−to−Source On−Resistance (VGS = 5 V, ID = 20 A) Low−Side Driver Static Drain−to−Source On−Resistance (VGS = 5 V, ID = 20 A) http://onsemi.com 4 NIS3001A Average Input Voltage PIN = (VVS * IVS) + (VIN * IIN) POUT = (VOUT * IOUT) Efficiency = POUT/PIN PLOSS = PIN − POUT A V BST Average VS Voltage 5V + TG + − 12 V VIN VS A Average Output Current V Average − VS Current Average Input Current EN DRN Driver A Load PWM Signal CO GND BG PGND Averaging Circuit Average V Output Voltage This Test Circuit was used to characterize the NIS3001A during operation for Figures 4 to 24. Figure 3. Test Circuit Electrical and Thermal Characteristics 7. Electrical Measurements Performed as Defined in Figure 3 8. All Testing Performed in an Air Chamber Figures 13 through 24 represent the thermal performance under different electrical conditions at various air flows with and without heat sinking. The optimum heat sinking performance is obtained by using thermal pipes. The thermal pipes are soldered to the PCB at the switch node and VIN locations, next to the device. The pipes thermally connect the heat sink with the PCB but are electrically isolated from the heat sink. The heat sink is also connected to the top of the NIS3001A. The test boards used to measure the thermal and electrical performance have the following characteristics and were used for Figures 4 through 24. 1. PCB Size; 2” x 2.75” (FR4, 0.062” Thick). 2. 4 Layers, 2 oz Copper Clad 3. Heat Sink (6 fins, 1” long, 0.4” x 0.7” 4. Thermal Pipes (Copper Blocks, 0.2” x 0.2” 0.082” Thick), Soldered to PCB 5. Dielectric Thermal Tape; Electrically Isolates Pipes from Heat Sink 6. PCB Temperature Measured at Hottest Location on the Board http://onsemi.com 5 NIS3001A TYPICAL PERFORMANCE CURVES 98 TA = 25°C VIN = 12 V VVS = 5.0 V VOUT = 1.5 V Airflow = 200 lfm 10 8 750 kHz 500 kHz 6 350 kHz 4 94 90 88 86 750 kHz 82 0 FSW = 1000 kHz 80 0 5 10 15 20 25 30 5 10 IOUT, OUTPUT CURRENT (A) 15 20 25 IOUT, OUTPUT CURRENT (A) Figure 4. Power Loss versus Output Current Figure 5. Efficiency versus Output Current 23 35 TA = 25°C TA = 25°C VIN = 12 V IOUT = 15 A VOUT = 1.5 V VEN = 5 V Airflow = 200 lfm IVS, DRIVER CURRENT (mA) IVS, DRIVER CURRENT (mA) 500 kHz 350 kHz 92 84 2 21 TA = 25°C VIN = 12 V VVS = 5.0 V VOUT = 1.5 V Airflow = 200 lfm 96 FSW = 1000 kHz , EFFICIENCY (%) PLOSS, POWER LOSS (W) 12 19 FSW = 500 kHz 17 15 4.5 5 5.5 30 25 20 10 5 0 100 6 VIN = 12 V VS = 5.0 V IOUT = 15 A VOUT = 1.5 V VEN = 5 V Airflow = 200 lfm 15 VVS, DRIVER VOLTAGE (V) 200 300 400 500 600 700 800 900 1000 FSW, SWITCHING FREQUENCY (kHz) Figure 6. Driver Current versus Driver Voltage Figure 7. Driver Current versus Switching Frequency http://onsemi.com 6 NIS3001A 96 TA = 25°C VIN = 12.0 V IOUT = 15 A VOUT = 1.5 V VEN = 5.0 V Airflow = 200 lfm 2.7 2.6 FSW = 500 kHz 94 , EFFICIENCY (%) PLOSS, POWER LOSS (W) 2.8 2.5 FSW = 500 kHz 2.4 92 90 TA = 25°C VIN = 12 V IOUT = 15 A VS = 5.0 V Airflow = 200 Ifm 88 2.3 4.5 5.0 5.5 86 1.0 6.0 1.5 VVS, DRIVER VOLTAGE (V) 3.0 3.5 4.0 4.5 5.0 Figure 9. Efficiency versus Output Voltage 4.0 1.75 RDS(on), DRAIN−TO−SOURCE RESISTANCE (NORMALIZED) FSW = 500 kHz 3.5 3.0 TA = 25°C VIN = 12 V IOUT = 15 A VS = 5.0 V Airflow = 200 Ifm 2.5 1.5 2.0 2.5 3.0 3.5 4.0 1.25 1.00 0.75 0.50 −50 5.0 4.5 1.50 VGS = 5 V ID = 20 A RDS(on) = 8.1 m −25 VOUT, OUTPUT VOLTAGE (V) 0 25 VGS = 5 V ID = 20 A RDS(on) = 4.7 m 1.25 1.00 0.75 0.50 −50 −25 75 100 125 Figure 11. Top MOSFET On−Resistance Variation with Temperature 1.75 1.50 50 TJ, JUNCTION TEMPERATURE (°C) Figure 10. Power Loss versus Output Voltage RDS(on), DRAIN−TO−SOURCE RESISTANCE (NORMALIZED) PLOSS, POWER LOSS (W) 2.5 VOUT, OUTPUT VOLTAGE (V) Figure 8. Power Loss versus Driver Voltage 2.0 1.0 2.0 0 25 50 75 100 125 150 TJ, JUNCTION TEMPERATURE (°C) Figure 12. Bottom MOSFET On−Resistance Variation with Temperature http://onsemi.com 7 150 NIS3001A 35 TA = 25°C Vin = 12.0 V Vout = 1.1 V No Heat Sink 9 Iout, OUTPUT CURRENT (A) PLOSS, POWER LOS (W) 11 400 lfm 200 lfm 7 5 0 lfm 3 FSW = 500 kHz 1 60 70 TA = 25°C Vin = 12.0 V Vout =1.1 V No Heat Sink 30 200 lfm 25 20 0 lfm 15 FSW = 500 kHz 10 80 90 TPCB, TEMPERATURE (°C) 100 110 60 Figure 13. Power Loss versus PCB Temperature 80 90 100 TPCB, TEMPERATURE (°C) 110 Iout, OUTPUT CURRENT (A) 30 TA = 25°C Vin = 12.0 V Vout = 3.3 V No Heat Sink 8 PLOSS, POWER LOS (W) 70 Figure 14. Output Current versus PCB Temperature 10 400 lfm 200 lfm 6 0 lfm 4 2 TA = 25°C Vin = 12.0 V Vout = 3.3 V No Heat Sink 25 400 lfm 200 lfm 20 0 lfm 15 FSW = 500 kHz FSW = 500 kHz 0 10 60 70 80 90 100 110 60 70 80 90 100 TPCB, TEMPERATURE (°C) TPCB, TEMPERATURE (°C) Figure 15. Power Loss versus PCB Temperature Figure 16. Output Current versus PCB Temperature 10 110 30 TA = 25°C Vin = 12.0 V Vout = 5.1 V No Heat Sink 8 Iout, OUTPUT CURRENT (A) PLOSS, POWER LOS (W) 400 lfm 400 lfm 200 lfm 6 0 lfm 4 2 TA = 25°C Vin = 12.0 V Vout = 5.1 V 25 No Heat Sink 400 lfm 200 lfm 20 0 lfm 15 FSW = 500 kHz FSW = 500 kHz 10 0 60 70 80 90 100 110 60 70 80 90 100 TPCB, TEMPERATURE (°C) TPCB, TEMPERATURE (°C) Figure 17. Power Loss versus PCB Temperature Figure 18. Output Current versus PCB Temperature http://onsemi.com 8 110 NIS3001A 50 TA = 25°C Vin = 12.0 V Vout = 1.1 V 15 Heat Sink Iout, OUTPUT CURRENT (A) PLOSS, POWER LOSS (W) 20 400 lfm 200 lfm 10 0 lfm 5 FSW = 500 kHz 0 60 70 80 90 100 40 110 200 lfm 30 25 0 lfm 20 FSW = 500 kHz 70 80 90 100 TPCB, TEMPERATURE (°C) TPCB, TEMPERATURE (°C) Figure 19. Power Loss versus PCB Temperature Figure 20. Output Current versus PCB Temperature 110 40 Iout, OUTPUT CURRENT (A) TA = 25°C Vin = 12.0 V Vout = 3.3 V 15 Heat Sink 400 lfm 200 lfm 10 5 0 lfm 400 lfm 35 200 lfm 30 25 0 lfm 20 TA = 25°C Vin = 12.0 V Vout = 3.3 V Heat Sink 15 FSW = 500 kHz FSW = 500 kHz 0 10 60 70 80 90 TPCB, TEMPERATURE (°C) 100 110 60 70 Figure 21. Power Loss versus PCB Temperature 80 90 100 TPCB, TEMPERATURE (°C) 110 Figure 22. Output Current versus PCB Temperature 40 TA = 25°C Vin = 12.0 V Vout = 5.1 V 15 Heat Sink Iout, OUTPUT CURRENT (A) 20 PLOSS, POWER LOSS (W) 400 lfm 35 15 60 20 PLOSS, POWER LOSS (W) TA = 25°C Vin = 12.0 V Vout = 1.1 V Heat Sink 45 400 lfm 200 lfm 10 0 lfm 5 TA = 25°C Vin = 12.0 V Vout = 5.1 V Heat Sink 35 30 400 lfm 200 lfm 25 0 lfm 20 15 FSW = 500 kHz 0 60 FSW = 500 kHz 10 70 80 90 TPCB, TEMPERATURE (°C) 100 110 60 Figure 23. Power Loss versus PCB Temperature 70 80 90 100 TPCB, TEMPERATURE (°C) Figure 24. Output Current versus PCB Temperature http://onsemi.com 9 110 NIS3001A INTRODUCTION The NIS3001A represents a significant improvement in high frequency power conversion, by combining a high performance driver with two power MOSFET devices for use in synchronous buck converters. All three die are assembled in a QFN package called a PInPAK. This approach minimizes the parasitic elements in the power path by reducing the distance between the three devices. The leadless design also provides an excellent thermal path for the removal of heat which is generated during the power conversion process. All of these improvements result in a higher conversion efficiency when operation at high frequencies (350 kHz to 1000 kHz) is required. Operating at higher frequencies, reduces the number of electrolytic capacitors and the size of filter inductors required to meet load line and transient response requirements. This device is designed to process power from a nominal 12 volt source (ranging from 7 to 14 volts), while obtaining its internal bias power from a 5 volt supply. The output voltage can range from 0.7 to 5.1 volts with a maximum duty cycle of 50%. The NIS3001A requires signal inputs from a controller, such as the NCP5316. A minimum number of external components are required to create a complete power converter. Figure 25 is an example of a simplified solution. connected to the 12 volt input and the source is connected to the DRN pins. The drain of the bottom FET is also connected to the DRN pins, while its source is connected to the power ground pins. Functional Pin Description VS Pin: The VS pin connects to a nominal 5 volt supply and provides power to the driver chip. It is necessary to provide a bypass capacitor between 1.0 F and 10.0 F in close proximity to this pin and the ground (GND) pin. This capacitor allows a low impedance path for the high frequency currents that occur when the gate of the bottom FET switches. The voltage at this pin is monitored internally by the UVLO circuit which will disable the driver if there is not sufficient voltage available to assure proper operation of the driver. VIN Pin: The VIN pin connects to the nominal 12 volt supply which provides power to the switching stage of the converter. It connects to the drain of the top FET, which is the controlled switch of the buck converter. This pin needs a combination of electrolytic and ceramic capacitors for bypass purposes. Enable Pin: The EN pin accepts a logic level signal that can both source and sink current. There is no hysteresis on the signal switching levels for this pin, so care should be taken that the high and low logic levels of the driving signal should be above and below the switching points by several hundred millivolts. In its high state, the driver is operational and will respond to inputs on the CO pin. In its low state, the driver is disabled. In this state, it enters a reduced power mode and turns off both FETs, thereby providing a high impedance output at the DRN pin. A bypass capacitor is not normally required for the enable signal. Control Pin: The CO pin accepts a logic signal from the PWM output of the controller chip. This signal is fed into the driver and controls the top and bottom FETs. When this pin is in a high state, the top FET is fully enhanced and the bottom FET is not conducting. When the signal is low, the bottom FET is fully enhanced and the top FET is not conducting. During the switching transition, there is a non−overlap control circuit that is designed to provide optimum switching timing for the two FETs. This circuit eliminates the possibility of cross conduction, by monitoring the voltage on the DRN pin to time the turn−on of the bottom FET. Bootstrap Pin: The BST pin connects to an external diode−capacitor circuit that acts as a charge pump to provide a floating, isolated voltage source for the high−side driver. A Schottky diode is recommended, which charges the capacitor when the DRN pin is low. This diode is normally connected to the same source as the VS pin. The capacitor (typically 0.2 to 1.0 F) is connected from the BST to the DRN pin. The capacitor should be mounted as close as possible to the NIS3001A package. As there are Operational Description Driver: The internal driver requires a nominal 5 volt bias voltage to operate. The bootstrap voltage is normally derived from this same source. The bootstrap circuit typically employs a Schottky diode as part of the charge pump that provides the isolated supply voltage to the high side driver. The driver uses several control functions to provide the correct gate drive signals. The control (CO) input accepts the drive signal from the synchronous converter PWM. The driver circuitry programs a delay between the top and bottom FETs, such that they will not conduct at the same time. An enable pin (EN) allows the output of the driver to be shut down by a logic level signal. In this mode of operation, the bias current is reduced to a level of 10 A. When the driver is disabled, the gates of both FETs are low and the drain (DRN) output of the NIS3001A is in a high impedance state. To guarantee system integrity, the driver also incorporates an internal UVLO circuit. It is activated when the bias voltage reaches 4.25 volts, and will shut down the driver when if the bias voltage drops below 3.975 volts. In the UVLO shutdown condition, both FETs are off, and the DRN pin is in a high impedance state. Power MOSFETs: The NIS3001A contains two power FETs which are directly connected to the internal driver chip. They have different on resistances and are designed for optimum performance for current VRM voltage and current requirements. The drain of the top FET is http://onsemi.com 10 NIS3001A several DRN pins available, it is recommended that pin 14 be used because of its proximity to the BST pin. Drain Pin: The DRN pin is also called the switch node. It is the connection between the source of the top FET and the drain of the bottom FET. This node is connected to one terminal of the output filter inductor. When the top FET is conducting, the DRN pin is essentially connected to the 12 volt source. When the bottom FET is conducting, this node is essentially connected to ground. When the driver is disabled, this node is in a high impedance state, and is essentially connected to neither. Top Gate Pin: The TG pin is the internal connection of the output of the high−side driver and also the gate of the top FET. There is normally no connection to this pin. It can however, be used to drive an external FET which will operate in parallel with the top FET. This pin may also be attached to the pcb for additional heat sinking or used to monitor the top gate waveform. Bottom Gate Pin: The BG pin is the internal connection of the output of the lower driver and bottom FET gate. There is normally no connection to this pin, although it may be used for paralleling an additional FET, monitoring or heat sinking, similar to the TG pin. Power Ground: The PGND pin is the power ground for the device. The source of the bottom FET is also connected to this pin. This pin is not internally connected to the GND pin and care should be taken when laying out the circuit to maintain proper isolation between these grounds. Signal Ground: The GND pin is the ground pin for the driver, and is internally isolated from the PGND pin. b) c) d) e) Layout Considerations While the design of the NIS3001A reduces many of the parasitic elements when compared to a discrete solution, careful consideration to layout must still be observed. The following suggestions are offered: a) Mount the bootstrap capacitor very close to the package. Use DRN pin 14 and BST pin 17 due to f) their proximity. The capacitor should be a high quality ceramic type. Mount the VS pin bypass capacitor as close as possible to the package. This should be a high quality ceramic capacitor and is mounted between pins 4 and 2. VIN requires a combination of bypass capacitors. These consist of both low ESR aluminum electrolytics and high quality ceramics. The ceramics should be SMT devices and mounted as close to the VIN and PGND pins as possible. The aluminum capacitors are generally located slightly farther away, but should be connected via power and ground planes to maintain the lowest possible impedance. The total amount of capacitance required is dependant on the system requirements. Keep as much copper area as possible on all layers in the proximity of the device for best thermal performance. Especially, keep large copper areas connected to the large pads on the chip, and use thermal vias to transmit the heat to the bottom side of the board when possible. All vias underneath the chip, whether thermal or not should be plugged with epoxy or some material other than solder. The amount of solder paste used for mounting is important to a good connection. Empty vias can siphon off solder during the mounting process and leave voids, while soldered vias may contribute solder and cause shorts below the chip. Power and ground (PGND) busses should be distributed through power and ground planes. These should feed through vias to the appropriate pads for the 12 volts, switch node and ground connections. The impedances of the high current paths are critical for optimum efficiency. + − BST TG 12 V VIN VS 5V + − VOUT EN DRIVER DRN RL CO GND BG PGND Figure 25. http://onsemi.com 11 http://onsemi.com Figure 26. Application Diagram, Three−Phase Converter R59* R26 R502* GND ENABLE TPOINT ENABLE R11 VID5 VID0 VID1 VID2 VID3 VID4 LGND NC NC SGND PWRGD PWRLS R10 C3 R3 C1 R9 SSTART 1 2 3 4 5 6 7 8 9 10 11 12 Q41* Connects GND and AGND_A R22 TP2 SGND near socket VFFB connection GND D47* R60* R61* R8802* R27 R30 VSS_DIE PWRGD AGND_A VID5 JIF5.2 JIF4.2 JIF3.2 JIF2.2 JIF1.2 VCC3 C11* R24 5V 12 V Filter R25 LSCI R1 R8* C3A3 C2 R4* ATX 12 V R28 R5* R2 C2A2 C1A2 NCP5316 R15 C4 R501* R8801* NTC R12 Thermistor near closest R13 inductor C5 R16 36 35 34 33 32 31 30 29 28 27 26 25 R21 C6 R7 R54 R51 R45 CPU_VCC_SENSE R44 20, 21 15, 16 BG TG 1 CO BST 2 GND DRN 3 NIS3001 EN VIN 4 VS DRN PGND C61 5, 6 D45 R53 20, 21 15, 16 BG TG 1 CO BST 2 DRN GND 3 NIS3001 EN VIN 4 VS DRN PGND C56 5, 6 D44 R50 20, 21 15, 16 BG TG 1 CO BST 2 GND DRN 3 NIS3001 EN VIN 4 VS DRN PGND C46 5, 6 D42 12 V Filter * Optional If 5 V from silver box this resistor is used, otherwise it is removed CS1P ROSC VCC GATE1 GATE2 GATE3 GATE4 GATE5 GATE6 GND CS4P CS4N DRVON SS ENABLE VFFB VFB COMP NC NC CS6N CS6P CS5N CS5P 12 13 14 15 16 17 18 19 20 21 22 23 24 R29 R6* VCCL VREF IO IOF ILIM VDRP IPLIM CS3N CS3P CS2N CS2P CS1N 48 47 46 45 44 43 42 41 40 39 38 37 C4A1 C64 17 7−11 12, 13 14, 18 C62 C59 17 7−11 12, 13 14, 18 C57 C49 17 7−11 12, 13 14, 18 C47 C65 C60 C50 C63 R55 R20 C58 R52 R19 C48 R46 R17 L5 L4 L2 C10 C9 C7 VCCP Item 2 Qty. 10 GND Item 3 Qty. 40 VOUT NIS3001A NIS3001A 3 Phase Voltage Regulator (VRD) Recommended Bill of Materials Item Quantity Reference Rating Vendor Part Number Vendor Part Number 1 10 C1,C2,C3,C4,C5,C6,C7, C9,C10 10nF Value SM C0603 50V muRata GRM188R71H103KA01L TDK C1608X7R1H103K 2 10 C1B5,C1B6,C1B7,C2B12 C2B13,C2B14, 560F Size E, 8 x 10.5mm 4V SANYO OS−CON C2B15,C3B9,C3B10, C3B11 3 40 C2D1,C2C1,C2D2,C2C2, C2D3,C2C3, Size 3.5mm, 0.60mm SEPC Series 4SEPC560M(E13) ;+/−20% (M) 10F SM 1206 6.3V muRata GRM31CR70J106KA01L TDK C3216X5R0J106M C2D4,C2C4,C2D5,C2C5, C2D6,C2C6, C2D7,C2C7,C2D8,C2C8, C2D9,C2C9, C2D10,C2C10,C2D11, C2C11,C2D12, C2C12,C2C13,C2C14, C2C15,C2C16, C2C17,C2C18,C2C19, C2C20,C2C21, C2C22,C2C23,C2C24, C2C25,C2C26, C2C27,C2C28 4 6 C46,C47,C56,C57,C61, C62 1F SM C0805 16V muRata GRM21B71C105KA01L TDK C2012X7R1C105K 5 6 C49,C50,C59,C60,C64, C65 10F SM C1210 16V muRata GRM31CR61C106KC31L TDK C3225X7R1C106KT 6 3 C48,C58,C63 10nF SMC0603 16V muRata GRM188R71H103KA01L TDK C1608X7R1H103K 7 4 C4A1,C3A3,C2A2,C1A2 1800F 23X10 mm/5.5 mm 16V Rubycon 16 MBZ 1800 M 10X23 8 3 D42,D44,D45 Schottky SOT−23 30V/ 0.2A ON Semiconductor 9 3 L2,L4,L5 280nH 18.0 x 8.12 30Adc Coiltronics, Incorporated 10 1 L5C1 275nH 10.16 x 8.12 16Adc Coiltronics, Incorporated 11 2 R2,R1 6.65K R0805 “1%, 1/8 W” VISHAY CRCW08056651FRT1 12 2 R3,R7 10 _ R0805 “10%, 1/8W” VISHAY CRCW0805100JT1 13 1 R9 2.10K R0805 “1 %, 1/8W” VISHAY CRCW08052101FRT1 14 1 R10 15K R0805 “10%, 1/8W” VISHAY CRCW0805153JT1 15 1 R11 20 K R0805 “10%, 1/8W” VISHAY CRCW0805203JT1 16 1 R12 2.00 K R0805 “10%, 1/8W” VISHAY CRCW0805202JT1 17 1 R13 15K@ T=25°C R0805 200mW muRata NTC Thermistor TDK NTCG203NH153JT 18 1 R22 0_ R0805 “10%, 1/8W” VISHAY CRCW0805R00JT1 19 1 R15 1K R0805 “10%, 1/8 W” VISHAY CRCW0805102JT1 20 2 R16,R61 0_ R0805 “10%, 1/8W” VISHAY CRCW0805R00JT1 21 3 R17,R19,R20 18.2K R0805 “1%, 1/8 W” VISHAY CRCW08051822FT1 22 1 R21 63.4K R0805 “1%, 1/8 W” VISHAY CRCW08056342FT1 23 7 R24,R25,R26,R27,R28, R29,R30 1.5K R0805 “10%, 1/8W” VISHAY CRCW0805152JT1 24 6 R44,R45,R50,R51,R53, R54, 2.2_ R0805 “10%, 1/8W” VISHAY CRCW08052R2JT1 BAT54LT1 CTX15−14771 NCP21XW153J03RA R61 is used to connect the NIS3001A Vs pin to 5V supply only. If different voltage is required items 29 thru 33 are needed. http://onsemi.com 13 NIS3001A 3 Phase Voltage Regulator (VRD) Recommended Bill of Materials Item Quantity 25 3 R46,R52,R55 Reference 2.2_ Value SMR0603 Size Rating Vendor Part Number “10%, 1/10W” VISHAY CRCW06032R2JT1 26 1 U1 4/5/6 Phase IC LQFP−48 9 X 9 mm 27 1 PCB 4 layer 1 oz cCu ea 6.3 x 6.0 inches FR4 CGI Circuits 28 3 U42, U44, U45 Integrated Module 10.5 X 10.5 mm 30 Adc ON Semiconductor 50V muRata GRM188R71H103KA01L ON Semiconductor NCP5316 ONS 7 Rev C NIS3001A OPTIONAL PARTS 29 1 C11 10nF SM C0603 30 1 R59 1K R0805 “10%, 1/8W” VISHAY CRCW0805102JT1 31 1 R60 2.2_ R0805 “10%, 1/8W” VISHAY CRCW08052R2JT1 32 1 Q41 NPN Bipolar X−sistor SOT−223 30V/ 3A ON Semiconductor MMJT9410T1 33 1 D47 Zener Regulator SOT−23 0.225W/ 6.8 V ON Semiconductor BZX84C6V8LT1 34 2 R8801, R8802 N/A 35 2 R501, R502 N/A 36 4 R4, R5, R6, R8 N/A R61 is used to connect the NIS3001A Vs pin to 5V supply only. If different voltage is required items 29 thru 33 are needed. http://onsemi.com 14 Vendor Part Number NIS3001A APPLICATION INFORMATION INTRODUCTION Various ON Semiconductor components are packaged in an advanced Quad Flat−pack No−Lead Package (QFN) or commonly referred to as a Leadless Package. Because the QFN(Leadless) platform represent the latest in surface mount packaging technology, it is important that the design of the Printed Circuit Board (PCB), as well as the assembly process, follow the suggested guidelines outlined in this document. Typically, the NSMD pads are preferred over the SMD configuration since defining the location and size of the copper pad is easier to control than the solder mask. This is based on the fact that the copper etching process is capable of a tighter tolerance than the solder masking process. In addition, the SMD pads will inherently create a stress concentration point where the solder wets to the pad on top of the lead. This stress concentration point is eliminated when the solder is allowed to flow down the sides of the leads in the NSMD configuration. NIS3001A Package Overview The QFN platform offers a versatility, which allows either a single or multiple semiconductor devices to be connected together within a leadless package. In this case the NIS3001A Package contains multiple semiconductor devices within one package. This package style was chosen due to its excellent thermal dissipation and reduced electrical parasitics. When surface mounting this package onto a PCB, two critical issues must be considered: 1. Printed Circuit Board Design 2. Board Mounting Process. This document will address both of these critical issues. NSMD Pad Configurations When dimensionally possible, the solder mask should be located at least a ±0.076mm (0.003in) away from the edge of the solderable pad. This spacing is used to compensate for the registration tolerances of the solder mask, as well as to insure that the solder is not inhibited by the mask as it reflows along the sides of the metal pad. The dimensions of the soldermask openings are shown in Figure 28 for a preferred non−soldermask configuration. The dimensions of the PCB’s solderable pads should match those of the pads on the package as shown in Figure 29. The 1:1 ratio between the package’s pad configuration, and that of the PCB’s, is desired for optimal placement accuracy and reliability. Please note that NIS3001A Footprint shows smaller exposed pad openings compared with the recommended PCB layout. Die attach pads on the footprint were divided into smaller exposed pads to help reduce the risk of solder voiding during reflow mounting to the package Printed Circuit Board Design Considerations SMD and NSMD Pad Configurations There are two different types of PCB pad configurations commonly used for surface mount leadless QFN style packages. These different I/O configurations are: 1. Non Solder masked Defined (NSMD) 2. Solder Masked Defined (SMD) As their titles describe, the NSMD contact pads have the solder mask pulled away from the solderable metallization, while the SMD pads have the solder mask over the edge of the metallization, as shown in Figure 27. With the SMD Pads, the solder mask restricts the flow of solder paste on the top of the metallization which prevents the solder from flowing along the side of the metal pad. This is different from the NSMD configuration where the solder will flow around both the top and the sides of the metallization. 12X 0.508 12X 3.810 0.941 9.992 Solder Mask Opening 6.274 4.720 Solder Mask Overlay 1.765 1.765 Solderable Pad 6.745 Figure 28. NSMD Openings for PCB Layout NSMD SMD Figure 27. Comparison of NSMD versus SMD Pads http://onsemi.com 15 NIS3001A 2X 12X 1.689 0.356 12X 1.612 0.789 0.356 2X 3.261 3.439 3.658 0.789 3.261 9.840 4X 2X 1.612 R0.380 2.169 4.568 4X 2.861 2X 4X 1.612 1.612 3.096 NIS3001A Footprint 6.592 Recommended PCB Pattern for NIS3001A Footprint Figure 29. Recommended PCB Layout for NIS3001A Footprint Thermal/Electrical Vias The first metallization consists of an Organic Solderability Preservative coating (OSP) over the copper plated pad. The organic coating assists in reducing oxidation in order to preserve the copper metallization for soldering. The second recommended solderable metallization consists of plated electroless nickel over the copper pad, followed by immersion gold. The thickness of the electroless nickel layer is determined by the allowable internal material stresses and the temperature excursions the board will be subjected to throughout its lifetime. Even though the gold metallization is typically a self−limiting process, the thickness should be at least 0.05 mm thick, and not consist of more than 5% of the overall solder volume. Having excessive gold in the solder joint can create gold embitterment which may affect the reliability of the joint. Vias are normally placed on the larger die attach pads to improve electrical and thermal performance. If vias are required on the larger die attach pads, our recommendation is to use filled−vias. Filled−vias will help prevent the solder from flowing down into the holes, thereby reducing the solder volume required for the solder joint of this die attach pad. Filled−vias are normally filled with some type of conductive epoxy. If through−hole vias are used, we recommend that the via size be less than or equal to 0.25mm(10 mils). The number of vias placed over the die attach pad is also critical and should not exceed 25% of the total exposed area of the copper pattern. In other words, excessive through−hole vias will allow the solder to flow down into the via and thereby decrease the solder volume needed to have a sufficient solder joint. These vias can be plugged with solder mask material to avoid soldering wicking. Solder Type Solder paste such as Cookson Electronics’ WS3060 with a Type 3 or smaller sphere size is recommended. The WS3060 has a water−soluble flux for cleaning. Cookson Electronics’ PNC0106A can be used if a no−clean flux is preferred. NIS3001A Board Mounting Process The board mounting process is optimized by first defining and controlling the following processes: 1. Creating and maintaining a solderable metallization on the PCB contacts. 2. Choosing the proper solder paste. 3. Screening/stenciling the solder paste onto the PCB. 4. Placing the package onto the PCB. 5. Reflowing the solder paste. 6. Final solder joint inspection. Recommendations for each of these processes are located below. Solder Screening onto the PCB Stencil screening the solder onto the PCB board is commonly used in the industry. The recommended stencil thickness to be used is 0.075 mm (0.003 in) and the sidewalls of the stencil openings should be tapered approximately 5 degrees to facilitate the release of the paste when the stencil is removed from the PCB. Note that a 0.127 mm (0.005 in) thick stencil may be used also, but will require smaller stencil openings to reduce the amount of solder applied to equal the amount of solder applied using the 0.075 mm thick stencil. For a typical edge PCB terminal pad, the stencil opening should be the same size as the pad size on the package. However, in cases where the die pad is soldered to the PCB, the stencil opening must be divided into smaller openings PCB Solderable Metallization There are two common plated solderable metallizations, which are used for PCB surface mount devices. In either case, it is imperative that the plating is uniform, conforming, and free of impurities to insure a consistent solderable system. http://onsemi.com 16 NIS3001A as shown in Figure 30. Dividing the larger die pads into smaller screen openings reduces the risk of solder voiding and allows the solder joints for the smaller terminal pads to be at the same height as the larger ones. Temperature (C) 250 Package Placement onto the PCB Pick and place equipment with the standard tolerance of ±0.05 mm or better is recommended. The package will tend to center itself and correct for slight placement errors during the reflow process due to the surface tension of the solder. 12X 200 183 150 100 Less than 2°C/sec ÎÎ ÎÎÎ ÎÎ ÎÎÎ ÎÎ ÎÎÎ ÎÎÎÎÎ Time Soak Above Zone Liquidus (30 to 120 sec) 50 0 33X 0.356 Peak of 225°C 0 ∅ 0.700 100 200 300 400 500 Time (sec) 6X Figure 31. Typical Reflow Profile for Eutectic Tin/Lead Solder. 1.015 12X 0.789 In general, the temperature of the part should be raised not more than 2°C/sec during the initial stages of the reflow profile. The soak zone then occurs when the part is approximately 150°C and should last for 30 to 120 seconds. Typically, extending the time in the soak zone will reduce the risk of voiding within the solder. The temperature is then raised and will be above the liquidus of the solder for 30 to 100 seconds depending on the mass of the board. The peak temperature of the profile should be between 205 and 225°C for eutectic Sn/Pb solder. If required, removal of the residual solder flux can be completed by using the recommended procedures set forth by the flux manufacturer. Die Attach Pads 4X 1.621 2X 1.000 8X 0.811 8X 4X 0.928 1.856 Final Solder Inspection Figure 30. Solder stencil design illustrating smaller stencil openings over the larger exposed die pads. The inspection of the solder joints is commonly performed with the use of an X−ray inspection system. With this tool, one can locate defects such as shorts between pads, open contacts, voids within the solder as well as any extraneous solder. In addition to searching for defects, the mounted device should be rotated on its side to inspect the sides of the solder joints with an X−ray inspection system. The solder joints should have enough solder volume with the proper stand−off height so that an “Hour Glass” shaped connection is not formed as shown below in Figure 32. “Hour Glass” solder joints are a reliability concern and must be avoided. Solder Reflow Once the package is placed on the PC board along with the solder paste, a standard surface mount reflow process can be used to mount the part. Figure 31 is an example of a standard reflow profile. The exact profile will be determined, and is available, by the manufacture of the paste since the chemistry and viscosity of the flux matrix will vary. These variations will require small changes in the profile in order to achieve an optimized process. Preferred Solder Joint ÎÎ ÎÎ ÎÎPCB ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ Undesirable “Hour Glass” Solder Joint Figure 32. Side view of NIS3001A illustrating preferred and undesirable solder joints. http://onsemi.com 17 NIS3001A Rework Procedure proximity of the neighboring packages in most PC board configurations, a miniature stencil for the individual component is typically required. The same stencil design that was originally used to mount the package can be applied to the mini−stencil for redressing the pad. Due to the small pad configurations of the NIS3001A, and since the pads are on the underside of the package, a manual pick and place procedure without the aid of magnification is not recommended. A dual image optical system where the underside of the package can be aligned to the PC board should be used instead. Reflowing the component onto the board can be accomplished by either passing the board through the original reflow profile, or by selectively heating the NIS3001A Package with the same process that was used to remove it. The benefit with subjecting the entire board to a second reflow is that the packages will be mounted consistently and by a profile that is already defined. The disadvantage is that all of the other devices mounted with the same solder type will be reflowed for a second time. If subjecting all of the parts to a second is either a concern or unacceptable for a specific application, than the localized reflow option would be the recommended procedure. Due to the fact that the NIS3001A is a leadless device, the entire package must be removed from the PC board if there is an issue with the solder joints. It is important to minimize the chance of overheating neighboring devices during the removal of the package since the devices are typically in close proximity with each other. Standard SMT rework systems are recommended for this procedure since the airflow and temperature gradients can be carefully controlled. It is also recommend that the PC board be placed in an oven at 125°C for 4 to 8 hours prior to heating the parts to remove excess moisture from the packages. In order to control the region, which will be exposed to reflow temperatures, the board should be heated to a 100°C by conduction through the backside of the board in the location of the NIS3001A QFN Package. Typically, heating nozzles are then used to increase the temperature locally. Once the NIS3001A’s solder joints are heated above their liquidus temperature, the package is quickly removed and the pads on the PC board are cleaned. The cleaning of the pads is typically performed with a blade−style conductive tool with a de−soldering braid. A no clean flux is used during this process in order to simplify the procedure. Solder paste is then deposited or screened onto the site in preparation of mounting a new device. Due to the close http://onsemi.com 18 NIS3001A PACKAGE DIMENSIONS PInPAK 10.5x10.5 QFN CASE 500−02 ISSUE B A D 4X NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M, 1994. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSION APPLIES TO PLATED TERMINAL IS MEASURED BETWEEN 0.25 AND 0.30 MM FROM TERMINAL EDGE. 4. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. B 0.15 C DIM A A1 A2 A3 D E b e e1 e2 e3 e4 e5 F F1 F2 G G1 G2 H H1 H2 J K L L1 L2 N N1 N2 N3 N4 P P1 P2 P3 R R1 R2 R3 R4 E A A2 0.08 C A1 A3 C e DETAIL M SEATING PLANE NOTE 3 F 4X 9X P2 L1 0.10 M C A B 2X NOTE 3 0.10 P3 C A B M N L2 R 4X r = 0.38 2 X R4 e1 e3 CL e4 G H1 H G1 G2 CL N3 2 X R1 H2 J R2 MILLIMETERS MIN MAX 2.000 2.200 0.000 0.050 1.500 1.700 0.508 REF 10.500 BSC 10.500 BSC 0.306 0.406 3.496 BSC 3.261 BSC 1.969 BSC 2.424 BSC 0.762 BSC 0.762 BSC 0.124 BSC 0.037 BSC 4.114 BSC 0.229 BSC 3.200 BSC 3.289 BSC 1.424 BSC 0.283 BSC 2.188 BSC 3.048 BSC 2.286 BSC 0.154 0.354 0.230 0.430 0.230 0.430 2.936 BSC 1.495 BSC 2.197 BSC 2.361 BSC 2.663 BSC 1.512 1.712 1.589 1.789 2.996 3.196 1.512 1.712 2.761 2.961 3.161 3.361 3.339 3.539 0.689 0.889 2.094 2.244 N2 0.10 M 2 X P1 C A B e2 F1 F2 NOTE 3 CL P NOTE 3 0.10 M C A B 0.10 M C A B N1 e5 N4 12 X R3 8X L 12 X APPLIES TO ALL F AND G DIMENSIONS 0.10 M b K C A B CL NOTE 3 0.10 M C A B APPLIES TO ALL H AND N DIMENSIONS DETAIL M http://onsemi.com 19 NIS3001A PInPAK is a trademark of Semiconductor Components Industries, LLC. ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: N. American Technical Support: 800−282−9855 Toll Free Literature Distribution Center for ON Semiconductor USA/Canada P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Japan: ON Semiconductor, Japan Customer Focus Center 2−9−1 Kamimeguro, Meguro−ku, Tokyo, Japan 153−0051 Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada Phone: 81−3−5773−3850 Email: [email protected] http://onsemi.com 20 ON Semiconductor Website: http://onsemi.com Order Literature: http://www.onsemi.com/litorder For additional information, please contact your local Sales Representative. NIS3001A/D