FAN3223 / FAN3224 / FAN3225_F085 Dual 4A High-Speed, Low-Side Gate Drivers Features Description The FAN3223-25 family of dual 4A gate drivers is designed to drive N-channel enhancement-mode MOSFETs in low-side switching applications by providing high peak current pulses during the short switching intervals. The driver is available with either TTL or CMOS input thresholds. Internal circuitry provides an under-voltage lockout function by holding the output LOW until the supply voltage is within the operating range. In addition, the drivers feature matched internal propagation delays between A and B channels for applications requiring dual gate drives with critical timing, such as synchronous rectifiers. This also enables connecting two drivers in parallel to effectively double the current capability driving a single MOSFET. Qualified to AEC Q-100 4.5 to 18V Operating Range 5A Peak Sink/Source at VDD = 12V 4.3A Sink / 2.8A Source at VOUT = 6V Choice of TTL or CMOS Input Thresholds Three Versions of Dual Independent Drivers: - Dual Inverting + Enable (FAN3223) Dual Non-Inverting + Enable (FAN3224) Dual-Inputs (FAN3225) Internal Resistors Turn Driver Off If No Inputs Double Current Capability by Paralleling Channels MillerDrive™ Technology 12ns / 9ns Typical Rise/Fall Times with 2.2nF Load Typical Propagation Delay Under 20ns Matched within 1ns to the Other Channel 8-Lead SOIC Package Rated from –40°C to +125°C Ambient Applications Switch-Mode Power Supplies High-Efficiency MOSFET Switching Synchronous Rectifier Circuits DC-to-DC Converters Motor Control The FAN322X drivers incorporate MillerDrive™ architecture for the final output stage. This bipolarMOSFET combination provides high current during the Miller plateau stage of the MOSFET turn-on / turn-off process to minimize switching loss, while providing railto-rail voltage swing and reverse current capability. The FAN3223 offers two inverting drivers and the FAN3224 offers two non-inverting drivers. Each device has dual independent enable pins that default to ON if not connected. In the FAN3225, each channel has dual inputs of opposite polarity, which allows configuration as non-inverting or inverting with an optional enable function using the second input. If one or both inputs are left unconnected, internal resistors bias the inputs such that the output is pulled LOW to hold the power MOSFET OFF. Related Resources AN-6069: Application Review and Evaluation of Low-Side Gate Drivers FAN3223 FAN3224 Comparative FAN3225 Figure 1. Pin Configurations © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers August 2012 Part Number Logic Input Package Threshold Eco Status Packing Method Quantity per Reel FAN3223CMX_F085 Dual Inverting Channels + FAN3223TMX_F085 Dual Enable CMOS SOIC-8 RoHS Tape & Reel 2,500 TTL SOIC-8 RoHS Tape & Reel 2,500 FAN3224CMX_F085 Dual Non-Inverting Channels FAN3224TMX_F085 + Dual Enable CMOS SOIC-8 RoHS Tape & Reel 2,500 TTL SOIC-8 RoHS Tape & Reel 2,500 FAN3225CMX_F085 Dual Channels of Two-Input / FAN3225TMX_F085 One-Output Drivers CMOS SOIC-8 RoHS Tape & Reel 2,500 TTL SOIC-8 RoHS Tape & Reel 2,500 For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html. Package Outline Figure 2. SOIC-8 (Top View) Thermal Characteristics(1) Package 8-Pin Small Outline Integrated Circuit (SOIC) ΘJL(2) ΘJT(3) ΘJA(4) ΨJB(5) ΨJT(6) Units 38 29 87 41 2.3 °C/W Notes: 1. 2. 3. 4. 5. 6. Estimates derived from thermal simulation; actual values depend on the application. Theta_JL (ΘJL): Thermal resistance between the semiconductor junction and the bottom surface of all the leads (including any thermal pad) that are typically soldered to a PCB. Theta_JT (ΘJT): Thermal resistance between the semiconductor junction and the top surface of the package, assuming it is held at a uniform temperature by a top-side heatsink. Theta_JA (ΘJA): Thermal resistance between junction and ambient, dependent on the PCB design, heat sinking, and airflow. The value given is for natural convection with no heatsink using a 2S2P board, as specified in JEDEC standards JESD51-2, JESD51-5, and JESD51-7, as appropriate. Psi_JB (ΨJB): Thermal characterization parameter providing correlation between semiconductor junction temperature and an application circuit board reference point for the thermal environment defined in Note 4. For the SOIC-8 package, the board reference is defined as the PCB copper adjacent to pin 6. Psi_JT (ΨJT): Thermal characterization parameter providing correlation between the semiconductor junction temperature and the center of the top of the package for the thermal environment defined in Note 4. © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 2 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Ordering Information FAN3224 FAN3225 Figure 3. Pin Assignments (Repeated) Pin Definitions Name Pin Description ENA Enable Input for Channel A. Pull pin LOW to inhibit driver A. ENA has TTL thresholds for both TTL and CMOS INx threshold. ENB Enable Input for Channel B. Pull pin LOW to inhibit driver B. ENB has TTL thresholds for both TTL and CMOS INx threshold. GND Ground. Common ground reference for input and output circuits. INA Input to Channel A. INA+ Non-Inverting Input to Channel A. Connect to VDD to enable output. INA- Inverting Input to Channel A. Connect to GND to enable output. INB Input to Channel B. INB+ Non-Inverting Input to Channel B. Connect to VDD to enable output. INB- Inverting Input to Channel B. Connect to GND to enable output. OUTA Gate Drive Output A: Held LOW unless required input(s) are present and VDD is above UVLO threshold. OUTB Gate Drive Output B: Held LOW unless required input(s) are present and VDD is above UVLO threshold. OUTA Gate Drive Output A (inverted from the input): Held LOW unless required input is present and VDD is above UVLO threshold. OUTB Gate Drive Output B (inverted from the input): Held LOW unless required input is present and VDD is above UVLO threshold. Supply Voltage. Provides power to the IC. VDD Output Logic FAN3223 (x=A or B) FAN3224 (x=A or B) ENx INx OUTx ENx 0 0 0 0 0 (7) 0 0 (7) 0 1 (7) (7) 1 1 1 1 0 INx (7) 0 0 1 0 0 (7) 0 0 (7) 1 INx+ (7) 0 1 OUTx FAN3225 (x=A or B) 1 1 (7) INx− OUTx 0 0 (7) 0 1 0 1 1 (7) 0 (7) 1 1 Note: 7. Default input signal if no external connection is made. © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 3 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers FAN3223 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Block Diagrams Figure 4. FAN3223 Block Diagram Figure 5. FAN3224 Block Diagram © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 4 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Block Diagrams Figure 6. FAN3225 Block Diagram © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 5 Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol Parameter Min. Max. Unit -0.3 20.0 V VDD VDD to PGND VEN ENA and ENB to GND GND - 0.3 VDD + 0.3 V VIN INA, INA+, INA–, INB, INB+ and INB– to GND GND - 0.3 VDD + 0.3 V OUTA and OUTB to GND GND - 0.3 VDD + 0.3 V VOUT TL Lead Soldering Temperature (10 Seconds) TJ Junction Temperature TSTG Storage Temperature ESD Human Body Model, JEDEC JESD22-A114 +260 ºC -55 +150 ºC -65 +150 ºC 3 kV Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings. Symbol Parameter Min. Max. Unit 4.5 18.0 V VDD Supply Voltage Range VEN Enable Voltage ENA and ENB 0 VDD V VIN Input Voltage INA, INA+, INA–, INB, INB+ and INB– 0 VDD V TA Operating Ambient Temperature -40 +125 ºC © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 6 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Absolute Maximum Ratings Unless otherwise noted, VDD=12V, TJ=-40°C to +125°C. Currents are defined as positive into the device and negative out of the device. Symbol Parameter Conditions Min. Typ. Max. Unit Supply VDD Operating Range IDD Supply Current, Inputs / EN Not Connected FAN3225C VON Turn-On Voltage INA=ENA=VDD, INB=ENB=0V VOFF Turn-Off Voltage INA=ENA=VDD, INB=ENB=0V Inputs (FAN322xT) 4.5 18.0 V 0.70 0.95 mA 0.21 0.35 mA 3.4 3.9 4.5 V 3.2 3.7 4.3 V 0.8 1.2 All except FAN3225C (8) (9) VINL_T INx Logic Low Threshold VINH_T INx Logic High Threshold IINx_T Non-inverting Input Current IN = 0V -1.5 IINx_T Non-inverting Input Current IN = VDD 90 IINx_T Inverting Input Current IN = 0V -175.0 IINx_T Inverting Input Current IN = VDD -1.5 VHYS_T 1.6 TTL Logic Hysteresis Voltage Inputs (FAN322xC) 2.0 V 1.5 µA 120 175.0 µA -120 -90 µA 1.5 µA 1.0 V 0.4 0.7 30 38 (9) VINL_C INx Logic Low Threshold VINH_C INx Logic High Threshold IINx_C Non-Inverting Input Current IN = 0V -1.5 IINx_C Non-Inverting Input Current IN = VDD IINx_C Inverting Input Current IINx_C Inverting Input Current VHYS_C V %VDD 55 70 %VDD 1.5 µA 90 120 175 µA IN = 0V -175 -120 -90 µA IN = VDD -1.5 1.5 µA CMOS Logic Hysteresis Voltage 17 %VDD 1.2 V ENABLE (FAN3223C, FAN3223T, FAN3224C, FAN3224T) VENL Enable Logic Low Threshold VENH Enable Logic High Threshold VHYS_T RPU tD3 tD4 TTL Logic Hysteresis Voltage EN from 5V to 0V 0.8 EN from 0V to 5V 1.6 (10) (10) Enable Pull-up Resistance 2.0 V 0.4 V 100 kΩ EN to Output Propagation Delay (11) 0V to 5V EN, 1V/ns Slew Rate 9 17 29 ns EN to Output Propagation Delay (11) 5V to 0V EN, 1V/ns Slew Rate 9 18 31 ns Continued on the following page… © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 7 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Electrical Characteristics Unless otherwise noted, VDD=12V, TJ=-40°C to +125°C. Currents are defined as positive into the device and negative out of the device. Symbol Parameter Conditions Min. Typ. Max. Unit Output ISINK (10) OUT Current, Mid-Voltage, Sinking (10) ISOURCE OUT Current, Mid-Voltage, Sourcing IPK_SINK OUT Current, Peak, Sinking IPK_SOURCE (10) OUT Current, Peak, Sourcing (10) OUT at VDD/2, CLOAD=0.22µF, f=1kHz 4.3 A OUT at VDD/2, CLOAD=0.22µF, f=1kHz -2.8 A CLOAD=0.22µF, f=1kHz 5 A CLOAD=0.22µF, f=1kHz -5 A VOH High Level Output Voltage VOH = VDD – VOUT, IOUT = –1mA 15 35 mV VOL Low Level Output Voltage IOUT = 1mA 10 25 mV CLOAD=2200pF 12 20 ns Output Fall Time CLOAD=2200pF 9 17 ns tD1, tD2 Output Propagation Delay, CMOS (12) Inputs 0 - 12VIN, 1V/ns Slew Rate 9 18 34 ns tD1, tD2 Output Propagation Delay, TTL Inputs 0 - 5VIN, 1V/ns Slew Rate 9 17 29 ns Propagation Matching Between Channels INA=INB, OUTA and OUTB at 50% point 2 4 ns tRISE tFALL TDEL.MATCH IRVS (11) Output Rise Time (11) (12) (10) Output Reverse Current Withstand 500 mA Notes: 8. Lower supply current due to inactive TTL circuitry. 9. EN inputs have TTL thresholds; refer to the ENABLE section 10. Not tested in production. 11. See Timing Diagrams of Figure 9 and Figure 10. 12. See Timing Diagrams of Figure 7 and Figure 8. © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 8 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Electrical Characteristics (Continued) 90% Output 10% Input VINH VINL tD1 tD2 t RISE t FALL Figure 7. Non-Inverting (EN HIGH or Floating) Figure 8. Inverting (EN HIGH or Floating) Figure 9. Non-Inverting (IN HIGH) Figure 10. Inverting (IN LOW) © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 9 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Timing Diagrams Typical characteristics are provided at 25°C and VDD=12V unless otherwise noted. (13) (13) Figure 11. IDD (Static) vs. Supply Voltage Figure 12. IDD (Static) vs. Supply Voltage Figure 13. IDD (Static) vs. Supply Voltage Figure 14. IDD (No-Load) vs. Frequency © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 (13) Figure 15. IDD (No-Load) vs. Frequency www.fairchildsemi.com 10 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Performance Characteristics Typical characteristics are provided at 25°C and VDD=12V unless otherwise noted. Figure 16. IDD (2.2nF Load) vs. Frequency Figure 17. IDD (2.2nF Load) vs. Frequency (13) (13) Figure 18. IDD (Static) vs. Temperature Figure 19. IDD (Static) vs. Temperature (13) Figure 20. IDD (Static) vs. Temperature © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 11 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Performance Characteristics Typical characteristics are provided at 25°C and VDD=12V unless otherwise noted. Figure 21. Input Thresholds vs. Supply Voltage Figure 22. Input Thresholds vs. Supply Voltage Figure 23. Input Threshold % vs. Supply Voltage Figure 24. Input Thresholds vs. Temperature © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 Figure 25. Input Thresholds vs. Temperature www.fairchildsemi.com 12 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Performance Characteristics Typical characteristics are provided at 25°C and VDD=12V unless otherwise noted. Figure 26. UVLO Thresholds vs. Temperature Figure 27. UVLO Threshold vs. Temperature Figure 28. Propagation Delay vs. Supply Voltage Figure 29. Propagation Delay vs. Supply Voltage Figure 30. Propagation Delay vs. Supply Voltage Figure 31. Propagation Delay vs. Supply Voltage © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 13 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Performance Characteristics Typical characteristics are provided at 25°C and VDD=12V unless otherwise noted. Figure 32. Propagation Delays vs. Temperature Figure 33. Propagation Delays vs. Temperature Figure 34. Propagation Delays vs. Temperature Figure 35. Propagation Delays vs. Temperature Figure 36. Fall Time vs. Supply Voltage © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 Figure 37. Rise Time vs. Supply Voltage www.fairchildsemi.com 14 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Performance Characteristics FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Performance Characteristics Typical characteristics are provided at 25°C and VDD=12V unless otherwise noted. Figure 38. Rise and Fall Times vs. Temperature Figure 39. Rise/Fall Waveforms with 2.2nF Load Figure 40. Rise/Fall Waveforms with 10nF Load Figure 41. Quasi-Static Source Current (14) with VDD=12V © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 (14) Figure 42. Quasi-Static Sink Current with VDD=12V www.fairchildsemi.com 15 Typical characteristics are provided at 25°C and VDD=12V unless otherwise noted. Figure 43. Quasi-Static Source Current (14) with VDD=8V (14) Figure 44. Quasi-Static Sink Current with VDD=8V Notes: 13. For any inverting inputs pulled low, non-inverting inputs pulled high, or outputs driven high, static IDD increases by the current flowing through the corresponding pull-up/down resistor shown in the block diagram. 14. The initial spike in each current waveform is a measurement artifact caused by the stray inductance of the current-measurement loop. Test Circuit Figure 45. Quasi-Static IOUT / VOUT Test Circuit © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 16 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Performance Characteristics Input Thresholds MillerDrive™ Gate Drive Technology Each member of the FAN322x driver family consists of two identical channels that may be used independently at rated current or connected in parallel to double the individual current capacity. In the FAN3223 and FAN3224, channels A and B can be enabled or disabled independently using ENA or ENB, respectively. The EN pin has TTL thresholds for parts with either CMOS or TTL input thresholds. If ENA and ENB are not connected, an internal pull-up resistor enables the driver channels by default. ENA and ENB have TTL thresholds in parts with either TTL or CMOS INx threshold. If the channel A and channel B inputs and outputs are connected in parallel to increase the driver current capacity, ENA and ENB should be connected and driven together. FAN322x gate drivers incorporate the MillerDrive™ architecture shown in Figure 46. For the output stage, a combination of bipolar and MOS devices provide large currents over a wide range of supply voltage and temperature variations. The bipolar devices carry the bulk of the current as OUT swings between 1/3 to 2/3 VDD and the MOS devices pull the output to the HIGH or LOW rail. The purpose of the MillerDrive™ architecture is to speed up switching by providing high current during the Miller plateau region when the gate-drain capacitance of the MOSFET is being charged or discharged as part of the turn-on / turn-off process. For applications that have zero voltage switching during the MOSFET turn-on or turn-off interval, the driver supplies high peak current for fast switching even though the Miller plateau is not present. This situation often occurs in synchronous rectifier applications because the body diode is generally conducting before the MOSFET is switched ON. The FAN322x family offers versions in either TTL or CMOS input thresholds. In the FAN322xT, the input thresholds meet industry-standard TTL-logic thresholds independent of the VDD voltage, and there is a hysteresis voltage of approximately 0.4V. These levels permit the inputs to be driven from a range of input logic signal levels for which a voltage over 2V is considered logic HIGH. The driving signal for the TTL inputs should have fast rising and falling edges with a slew rate of 6V/µs or faster, so a rise time from 0 to 3.3V should be 550ns or less. With reduced slew rate, circuit noise could cause the driver input voltage to exceed the hysteresis voltage and retrigger the driver input, causing erratic operation. The output pin slew rate is determined by VDD voltage and the load on the output. It is not user adjustable, but a series resistor can be added if a slower rise or fall time at the MOSFET gate is needed. VDD In the FAN322xC, the logic input thresholds are dependent on the VDD level and, with VDD of 12V, the logic rising edge threshold is approximately 55% of VDD and the input falling edge threshold is approximately 38% of VDD. The CMOS input configuration offers a hysteresis voltage of approximately 17% of VDD. The CMOS inputs can be used with relatively slow edges (approaching DC) if good decoupling and bypass techniques are incorporated in the system design to prevent noise from violating the input voltage hysteresis window. This allows setting precise timing intervals by fitting an R-C circuit between the controlling signal and the IN pin of the driver. The slow rising edge at the IN pin of the driver introduces a delay between the controlling signal and the OUT pin of the driver. Input stage Figure 46. MillerDrive™ Output Architecture Under-Voltage Lockout The FAN322x start-up logic is optimized to drive ground-referenced N-channel MOSFETs with an undervoltage lockout (UVLO) function to ensure that the IC starts up in an orderly fashion. When VDD is rising, yet below the 3.9V operational level, this circuit holds the output LOW, regardless of the status of the input pins. After the part is active, the supply voltage must drop 0.2V before the part shuts down. This hysteresis helps prevent chatter when low VDD supply voltages have noise from the power switching. This configuration is not suitable for driving high-side P-channel MOSFETs because the low output voltage of the driver would turn the P-channel MOSFET ON with VDD below 3.9V. Static Supply Current In the IDD (static) typical performance characteristics (Figure 11 - Figure 13 and Figure 18 - Figure 20), the curve is produced with all inputs/enables floating (OUT is low) and indicates the lowest static IDD current for the tested configuration. For other states, additional current flows through the 100kΩ resistors on the inputs and outputs shown in the block diagram of each part (see Figure 6). In these cases, the actual static IDD current is the value obtained from the curves plus this additional current. © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 VOUT www.fairchildsemi.com 17 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Applications Information To enable this IC to turn a device ON quickly, a local high-frequency bypass capacitor CBYP with low ESR and ESL should be connected between the VDD and GND pins with minimal trace length. This capacitor is in addition to bulk electrolytic capacitance of 10µF to 47µF commonly found on driver and controller bias circuits. The FAN322x is compatible with many other industry-standard drivers. In single input parts with enable pins, there is an internal 100kΩ resistor tied to VDD to enable the driver by default; this should be considered in the PCB layout. The turn-on and turn-off current paths should be minimized, as discussed in the following section. Figure 47 shows the pulsed gate drive current path when the gate driver is supplying gate charge to turn the MOSFET ON. The current is supplied from the local bypass capacitor, CBYP, and flows through the driver to the MOSFET gate and to ground. To reach the high peak currents possible, the resistance and inductance in the path should be minimized. The localized CBYP acts to contain the high peak current pulses within this driverMOSFET circuit, preventing them from disturbing the sensitive analog circuitry in the PWM controller. A typical criterion for choosing the value of CBYP is to keep the ripple voltage on the VDD supply to ≤5%. This is often achieved with a value ≥20 times the equivalent load capacitance CEQV, defined here as QGATE/VDD. Ceramic capacitors of 0.1µF to 1µF or larger are common choices, as are dielectrics, such as X5R and X7R with good temperature characteristics and high pulse current capability. If circuit noise affects normal operation, the value of CBYP may be increased to 50-100 times the CEQV, or CBYP may be split into two capacitors. One should be a larger value, based on equivalent load capacitance, and the other a smaller value, such as 1-10nF mounted closest to the VDD and GND pins to carry the higher frequency components of the current pulses. The bypass capacitor must provide the pulsed current from both of the driver channels and, if the drivers are switching simultaneously, the combined peak current sourced from the CBYP would be twice as large as when a single channel is switching. Layout and Connection Guidelines The FAN3223-25 family of gate drivers incorporates fast-reacting input circuits, short propagation delays, and powerful output stages capable of delivering current peaks over 4A to facilitate voltage transition times from under 10ns to over 150ns. The following layout and connection guidelines are strongly recommended: Keep high-current output and power ground paths separate logic and enable input signals and signal ground paths. This is especially critical when dealing with TTL-level logic thresholds at driver inputs and enable pins. Keep the driver as close to the load as possible to minimize the length of high-current traces. This reduces the series inductance to improve highspeed switching, while reducing the loop area that can radiate EMI to the driver inputs and surrounding circuitry. If the inputs to a channel are not externally connected, the internal 100kΩ resistors indicated on block diagrams command a low output. In noisy environments, it may be necessary to tie inputs of an unused channel to VDD or GND using short traces to prevent noise from causing spurious output switching. Many high-speed power circuits can be susceptible to noise injected from their own output or other external sources, possibly causing output retriggering. These effects can be obvious if the circuit is tested in breadboard or non-optimal circuit layouts with long input, enable, or output leads. For best results, make connections to all pins as short and direct as possible. © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 Figure 47. Current Path for MOSFET Turn-on Figure 48 shows the current path when the gate driver turns the MOSFET OFF. Ideally, the driver shunts the current directly to the source of the MOSFET in a small circuit loop. For fast turn-off times, the resistance and inductance in this path should be minimized. Figure 48. Current Path for MOSFET Turn-off www.fairchildsemi.com 18 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers VDD Bypass Capacitor Guidelines Operational Waveforms The FAN3225 truth table indicates the operational states using the dual-input configuration. In a non-inverting driver configuration, the IN- pin should be a logic LOW signal. If the IN- pin is connected to logic HIGH, a disable function is realized, and the driver output remains LOW regardless of the state of the IN+ pin. At power-up, the driver output remains LOW until the VDD voltage reaches the turn-on threshold. The magnitude of the OUT pulses rises with VDD until steady-state VDD is reached. The non-inverting operation illustrated in Figure 51 shows that the output remains LOW until the UVLO threshold is reached, then the output is in-phase with the input. IN+ IN- OUT 0 0 0 0 1 0 1 0 1 1 1 0 In the non-inverting driver configuration in Figure 49, the IN- pin is tied to ground and the input signal (PWM) is applied to IN+ pin. The IN- pin can be connected to logic HIGH to disable the driver and the output remains LOW, regardless of the state of the IN+ pin. Figure 51. Non-Inverting Start-Up Waveforms For the inverting configuration of Figure 50, start-up waveforms are shown in Figure 52. With IN+ tied to VDD and the input signal applied to IN–, the OUT pulses are inverted with respect to the input. At powerup, the inverted output remains LOW until the VDD voltage reaches the turn-on threshold, then it follows the input with inverted phase. Figure 49. Dual-Input Driver Enabled, Non-Inverting Configuration In the inverting driver application in Figure 50, the IN+ pin is tied HIGH. Pulling the IN+ pin to GND forces the output LOW, regardless of the state of the IN- pin. Figure 50. Dual-Input Driver Enabled, Inverting Configuration Figure 52. Inverting Start-Up Waveforms © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 19 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Truth Table of Logic Operation Thermal Guidelines Gate drivers used to switch MOSFETs and IGBTs at high frequencies can dissipate significant amounts of power. It is important to determine the driver power dissipation and the resulting junction temperature in the application to ensure that the part is operating within acceptable temperature limits. To give a numerical example, if the synchronous rectifier switches in the forward converter of Figure 53 are FDMS8660S, the datasheet gives a total gate charge of 60nC at VGS = 7V, so two devices in parallel would have 120nC gate charge. At a switching frequency of 300kHz, the total power dissipation is: The total power dissipation in a gate driver is the sum of two components, PGATE and PDYNAMIC: PTOTAL = PGATE + PDYNAMIC (1) Gate Driving Loss: The most significant power loss results from supplying gate current (charge per unit time) to switch the load MOSFET ON and OFF at the switching frequency. The power dissipation that results from driving a MOSFET at a specified gatesource voltage, VGS, with gate charge, QG, at switching frequency, FSW, is determined by: PGATE = QG • VGS • FSW • n (5) PDYNAMIC = 1.5mA • 7V • 2 = 0.021W (6) PTOTAL = 0.525W (7) The SOIC-8 has a junction-to-board thermal characterization parameter of ψJB = 42°C/W. In a system application, the localized temperature around the device is a function of the layout and construction of the PCB along with airflow across the surfaces. To ensure reliable operation, the maximum junction temperature of the device must be prevented from exceeding the maximum rating of 150°C; with 80% derating, TJ would be limited to 120°C. Rearranging Equation 4 determines the board temperature required to maintain the junction temperature below 120°C: (2) n is the number of driver channels in use (1 or 2). Dynamic Pre-drive / Shoot-through Current: A power loss resulting from internal current consumption under dynamic operating conditions, including pin pull-up / pull-down resistors, can be obtained using the “IDD (No-Load) vs. Frequency” graphs in Typical Performance Characteristics to determine the current IDYNAMIC drawn from VDD under actual operating conditions: PDYNAMIC = IDYNAMIC • VDD • n PGATE = 120nC • 7V • 300kHz • 2 = 0.504W TB,MAX = TJ - PTOTAL • ψJB (8) TB,MAX = 120°C – 0.525W • 42°C/W = 98°C (9) (3) Once the power dissipated in the driver is determined, the driver junction rise with respect to circuit board can be evaluated using the following thermal equation, assuming ψJB was determined for a similar thermal design (heat sinking and air flow): TJ = PTOTAL • ψJB + TB (4) where: = driver junction temperature TJ ψJB = (psi) thermal characterization parameter relating temperature rise to total power dissipation TB = board temperature in location as defined in the Thermal Characteristics table. © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 20 FAN3224 ENB 8 1 ENA A 2 3 GND 4 Figure 53. High Current Forward Converter with Synchronous Rectification Figure 54. B 7 VDD 6 5 Center-tapped Bridge Output with Synchronous Rectifiers Figure 55. Secondary Controlled Full Bridge with Current Doubler Output, Synchronous Rectifiers (Simplified) © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 21 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Typical Application Diagrams Type Related Products Part Number (15) Gate Drive (Sink/Src) Input Threshold Logic Single Channel of Dual-Input/Single-Output Package Single 1A FAN3111C +1.1A / -0.9A CMOS Single 1A FAN3111E +1.1A / -0.9A External Single 2A FAN3100C +2.5A / -1.8A CMOS Single Channel of Two-Input/One-Output SOT23-5 Single 2A FAN3100T +2.5A / -1.8A TTL Single Channel of Two-Input/One-Output SOT23-5 Dual 2A FAN3216T +2.4A / -1.6A TTL Dual Inverting Channels SOIC8 Dual 2A FAN3217T +2.4A / -1.6A TTL Dual Non-Inverting Channels SOIC8 Dual 2A FAN3226C +2.4A / -1.6A CMOS Dual Inverting Channels + Dual Enable SOIC8 Dual 2A FAN3226T +2.4A / -1.6A TTL Dual Inverting Channels + Dual Enable SOIC8 Dual 2A FAN3227C +2.4A / -1.6A CMOS Dual Non-Inverting Channels + Dual Enable SOIC8 Dual 2A FAN3227T +2.4A / -1.6A TTL Dual Non-Inverting Channels + Dual Enable SOIC8 Dual 2A FAN3228C +2.4A / -1.6A CMOS Dual Channels of Two-Input/One-Output, Pin Config.1 SOIC8 Dual 2A FAN3228T +2.4A / -1.6A TTL Dual Channels of Two-Input/One-Output, Pin Config.1 SOIC8 Dual 2A FAN3229C +2.4A / -1.6A CMOS Dual Channels of Two-Input/One-Output, Pin Config.2 SOIC8 Dual 2A FAN3229T +2.4A / -1.6A TTL Dual Channels of Two-Input/One-Output, Pin Config.2 SOIC8 Dual 2A FAN3268T +2.4A / -1.6A TTL 20V Non-Inverting Channel (NMOS) and Inverting Channel (PMOS) + Dual Enables SOIC8 Dual 2A FAN3278T +2.4A / -1.6A TTL 30V Non-Inverting Channel (NMOS) and Inverting Channel (PMOS) + Dual Enables SOIC8 Dual 4A FAN3213T +2.5A / -1.8A TTL Dual Inverting Channels SOIC8 Dual 4A FAN3214T +2.5A / -1.8A TTL Dual Non-Inverting Channels SOIC8 Dual 4A FAN3223C +4.3A / -2.8A CMOS Dual Inverting Channels + Dual Enable SOIC8 Dual 4A FAN3223T +4.3A / -2.8A TTL Dual Inverting Channels + Dual Enable SOIC8 Dual 4A FAN3224C +4.3A / -2.8A CMOS Dual Non-Inverting Channels + Dual Enable SOIC8 Dual 4A FAN3224T +4.3A / -2.8A TTL Dual Non-Inverting Channels + Dual Enable SOIC8 Dual 4A FAN3225C +4.3A / -2.8A CMOS Dual Channels of Two-Input/One-Output SOIC8 Dual 4A FAN3225T +4.3A / -2.8A TTL Dual Channels of Two-Input/One-Output SOIC8 Single 9A FAN3121C +9.7A / -7.1A CMOS Single Inverting Channel + Enable SOIC8 Single 9A FAN3121T +9.7A / -7.1A TTL Single Inverting Channel + Enable SOIC8 Single 9A FAN3122T +9.7A / -7.1A CMOS Single Non-Inverting Channel + Enable SOIC8 Single 9A FAN3122C +9.7A / -7.1A TTL Single Non-Inverting Channel + Enable SOIC8 (16) SOT23-5 Single Non-Inverting Channel with External Reference SOT23-5 Notes: 15. Typical currents with OUTx at 6V and VDD=12V. 16. Thresholds proportional to an externally supplied reference voltage. © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 22 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Table 1. 5.00 4.80 A 0.65 3.81 8 5 B 6.20 5.80 PIN ONE INDICATOR 1.75 4.00 3.80 1 5.60 4 1.27 (0.33) 0.25 M 1.27 C B A LAND PATTERN RECOMMENDATION 0.25 0.10 SEE DETAIL A 1.75 MAX R0.10 0.10 0.51 0.33 0.50 x 45? 0.25 C OPTION A - BEVEL EDGE GAGE PLANE R0.10 8? 0? 0.90 0.406 0.25 0.19 C OPTION B - NO BEVEL EDGE 0.36 NOTES: UNLESS OTHERWISE SPECIFIED A) THIS PACKAGE CONFORMS TO JEDEC MS-012, VARIATION AA, ISSUE C, B) ALL DIMENSIONS ARE IN MILLIMETERS. C) DIMENSIONS DO NOT INCLUDE MOLD FLASH OR BURRS. D) LANDPATTERN STANDARD: SOIC127P600X175-8M. E) DRAWING FILENAME: M08AREV13 SEATING PLANE (1.04) DETAIL A SCALE: 2:1 Figure 56. 8-Lead SOIC Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/ © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 23 FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers Physical Dimensions (Continued) FAN3223 / FAN3224 / FAN3225_F085 — Dual 4A High-Speed, Low-Side Gate Drivers © 2012 Fairchild Semiconductor Corporation FAN3223 / FAN3224 / FAN3225_F085 • Rev. 1.0.0 www.fairchildsemi.com 24