Datasheet MIC4609 (Microchip) - 24

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MIC4609 5.0 APPLICATION INFORMATION
Typical leakage currents for the bootstrap capacitor and IGBT/MOSFET are in the 100 nA range. The
5.1 Bootstrap Circuit
MIC4609 HS-pin-to-driver leakage current is generally higher with typical values in the 1 µA range (or higher The high-side gate drive cannot be operated at high junction temperature and voltage). The continuously (100% duty cycle). It must be periodically minimum value of bootstrap capacitor that prevents an turned off to refresh/recharge the bootstrap capacitor, excessive drop in the gate drive voltage to the CB. There are two separate requirements to consider high-side switch is calculated as per Equation 5-2. when choosing the bootstrap capacitor value: • IGBT or MOSFET gate charge
EQUATION 5-2:
• Duration of the high-side switch on-time t  C ON Idischarge  ------------------ The high-side bootstrap circuit for Phase A is illustrated B VHB in Figure 5-1. Where: tON = Maximum ON-time of the high-side D switch BST VIN VHB = Voltage drop at the HB pin CVDD *R C HB B AHB *R I V CB discharge = Total discharge current at the HB pin DD (capacitor, IGBT/MOSFET, and HB pin) AHO R AHI G Level Resistors R shift HB and RCB can be used to reduce the peak AHS RHS CB charge current or modify the high-side IGBT/MOSFET turn-on time. This helps reduce noise DCLAMP and EMI as well as ripple on the VDD pin. The resistor in series with the HB pin, RHB, controls the ALI ALO turn-on time of the high-side switch by limiting the RG charge current into the gate. Adding a resistor in series with capacitor CB will reduce the peak charging current drawn through diode DBST. It COM has some effect on slowing down the high-side switch turn-on time, however, it is not as effective as resistor * Optional Components RHB since charging current also comes from VDD until the high-side switch starts to turn on and raise the
FIGURE 5-1:
MIC4609 – Bootstrap Circuit. voltage on the HB node. The bootstrap capacitor voltage drops each time it delivers charge to turn on the IGBT. The voltage drop
5.2 HS Node Clamp
depends on the gate charge required by the IGBT. Most IGBT and MOSFET specifications contain gate charge A resistor/diode clamp between the switching node and versus V the HS pin is recommended to minimize large negative GE or VGS voltage information or graphs. Based on this information and a recommended V glitches or pulses on the HS pin. HB of 0.1V to 0.5V, the minimum value of bootstrap As shown in Figure 5-2, the high-side and low-side capacitance is calculated by applying Equation 5-1. IGBTs turn on and off to regulate motor speed. During the on-time, when the high-side IGBT is conducting,
EQUATION 5-1:
current flows into the motor. After the high-side IGBT turns off, and before the low-side IGBT turns on, there Q C GATE  -------- is a brief period of time (dead time) that prevents both B VHB IGBTs from being ON at the same time. During the Where: dead time, current from the motor flows through the diode in parallel with the low-side IGBT. Depending on QGATE = Total gate charge at VHB the diode characteristics (VF and turn-on time), the VHB = Voltage drop at the HB pin motor current and circuit parasitics, the initial negative After the high-side switch has turned on, the bootstrap voltage on the switch node can be several volts or capacitor will continue to discharge due to leakage more. currents in the bootstrap capacitor, the IGBT/MOSFET Even though the HS pin is rated for negative voltage, it gate-to-source and the driver (HS-pin-to-ground is good practice to clamp the HS pin with a resistor and leakage). diode to prevent excessive negative voltage from damaging the driver. Depending on the application and DS20005531C-page 24  2016-2019 Microchip Technology Inc. Document Outline 600V 3-Phase MOSFET/IGBT Driver Features Typical Applications General Description Package Type Functional Block Diagram MIC4609 – Top Level Circuit Functional Block Diagram MIC4609 – Phase x Drive Circuit Typical Application Circuit MIC4609 – 300V, 3-Phase Motor Driver 1.0 Electrical Characteristics Absolute Maximum Ratings Operating Ratings AC/DC Electrical Characteristics Temperature Characteristics 2.0 Typical Performance Curves FIGURE 2-1: VDD Quiescent Current vs. VDD Voltage. FIGURE 2-2: VDD Quiescent Current vs. Temperature. FIGURE 2-3: VHB Quiescent Current vs. VHB Voltage. FIGURE 2-4: VHB Quiescent Current vs. Temperature. FIGURE 2-5: VDD+HB Shutdown Current vs. Voltage. FIGURE 2-6: VDD+HB Shutdown Current vs. Temperature. FIGURE 2-7: VDD+HB Shutdown Current vs. Voltage. FIGURE 2-8: VDD+HB Shutdown Current vs. Temperature. FIGURE 2-9: VDD Operating Current vs. Frequency. FIGURE 2-10: VHB Operating Current vs. Frequency – One Phase. FIGURE 2-11: HO Output Sink ON-Resistance vs. VDD. FIGURE 2-12: HO Output Sink ON-Resistance vs. Temperature. FIGURE 2-13: LO Output Sink ON-Resistance vs. VDD. FIGURE 2-14: LO Output Sink ON-Resistance vs. Temperature. FIGURE 2-15: HO Output Source ON-Resistance vs. VDD. FIGURE 2-16: HO Output Source ON-Resistance vs. Temperature. FIGURE 2-17: LO Output Source ON-Resistance vs. VDD. FIGURE 2-18: LO Output Source ON-Resistance vs. Temperature. FIGURE 2-19: VDD/VHB ULVO vs. Temperature. FIGURE 2-20: Propagation Delay vs. VDD Voltage. FIGURE 2-21: Propagation Delay vs. Temperature. FIGURE 2-22: HO Rise Time vs. VDD Voltage. FIGURE 2-23: HO Fall Time vs. VDD Voltage. FIGURE 2-24: LO Rise Time vs. VDD Voltage. FIGURE 2-25: LO Fall Time vs. VDD Voltage. FIGURE 2-26: Rise/Fall Time vs. Temperature (VDD = 10V). FIGURE 2-27: Rise/Fall Time vs. Temperature (VDD = 20V). FIGURE 2-28: Dead Time vs. VDD Voltage. FIGURE 2-29: Dead Time vs. Temperature (VDD = 10V). FIGURE 2-30: Dead Time vs. Temperature (VDD = 20V). FIGURE 2-31: Overcurrent Threshold vs. VDD Voltage. FIGURE 2-32: Overcurrent Threshold vs. Temperature. FIGURE 2-33: Overcurrent Propagation Delay vs. VDD Voltage. FIGURE 2-34: Overcurrent Propagation Delay vs. Temperature. 3.0 Pin Descriptions TABLE 3-1: Pin Function Table 4.0 Functional Description 4.1 UVLO Protection 4.2 Startup and UVLO FIGURE 4-1: Startup and Fault Timing Diagram. TABLE 4-1: Operational Truth Table 4.3 Enable Inputs 4.4 Input Stage FIGURE 4-2: Input Stage Block Diagram. FIGURE 4-3: Minimum Pulse-Width Diagram. 4.5 Dead Time and Anti-Shoot-Through Protection FIGURE 4-4: Dead Time, Propagation Delay, and Rise/Fall-Time Diagram. 4.6 Low-Side Driver Output Stage FIGURE 4-5: Low-Side Driver Block Diagram. 4.7 High-Side Driver and Bootstrap Circuit FIGURE 4-6: High-Side Driver and Bootstrap Circuit Block Diagram. FIGURE 4-7: MIC4609 Motor Driver Typical Application – Phase A. 4.8 Overcurrent Protection Circuitry FIGURE 4-8: Overcurrent Fault Sequence. 5.0 Application Information 5.1 Bootstrap Circuit FIGURE 5-1: MIC4609 – Bootstrap Circuit. 5.2 HS Node Clamp FIGURE 5-2: Negative HS Pin Voltage. 5.3 Power Dissipation Considerations FIGURE 5-3: MIC4609 High-Side Driving an External IGBT. FIGURE 5-4: Typical Gate Charge vs. VGE. 5.4 Decoupling Capacitor Selection 5.5 Grounding, Component Placement, and Circuit Layout FIGURE 5-5: Turn-On Current Paths. FIGURE 5-6: Turn-Off Current Paths. 6.0 Packaging Information 6.1 Package Marking Information 28-Lead SOICW Package Outline and Recommended Land Pattern Appendix A: Revision History Revision C (September 2019) Revision B (November 2017) Revision A (March 2016) Product Identification System Trademark Worldwide Sales and Service