Welcome to the introduction to the Gate Driver Optocouplers. In the course, we will be introducing the Avago’s Gate Driver Optocouplers and the typical application.
Figure shown is a typical three phase induction motor. The six hex-bridge IGBT can be driven with a transformer gate drive, a discrete gate current amplifier drive, an integrated high voltage HVIC gate drive, or an optocoupler gate drive.
This is a Typical IGBT Gate Charge Curve. Where Qg is the total gate charge that can be picked readily from the IGBT data sheets, as depicted in the gate voltage vs. gate charge shown in Figure above. From the IGBT data sheets, we know that the turn-ON time, td(on) of the IGBT can be calculated using the equation as shown.
This is a typical Phototransistor Optocoupler block diagram and Electrical Specifications. From the specifications, we know that a typical phototransistor optocoupler can only output current of milliampere level. The output current can’t drive the IGBT.
Here are ACPL-332J block diagram and specification. The ACPL-332J which intelligent gate driver can output 2.5 A current. The output current can drive the IGBT easily.
Figure above is the HCPL-316J block diagram and key features. HCPL-316J,the Avago’s 2.5 Amp Gate Drive Optocoupler, has Integrated Desaturation (VCE) Detection and Fault Status Feedback ,which makes IGBT VCE fault protection compact, affordable, and easy-to-implement while satisfying worldwide safety and regulatory requirements. So, HCPL-316J can be used in lots of application easily.
The figure shows a concept for an external blanking circuit. This method uses one additional external resistor, RB, connected from the output to the DESAT pin 14 of the HCPL-316J gate driver. This allows an additional blanking capacitor charging current component from the output of the gate driver optocoupler through RB and this adds to the internal current source of the gate driver optocoupler. This higher external blanking capacitor charging current allows a designer greater flexibility in choosing both an appropriate value of the blanking capacitor, CB, and an appropriate current through the choice of the external resistor RB. By adjusting the capacitance of the blanking capacitor CB and the additional external blanking current through RB, a designer can set a specific precise blanking time.
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Transcript of "Use the Gate Driver Optocouplers for Variable Speed Motor Drives"
Use the Gate Driver Optocouplers for Variable Speed Motor Drives <ul><li>Source: Avago </li></ul>
Module Introduction <ul><li>Purpose </li></ul><ul><ul><li>This module introduce the Gate Driver Optocouplers. </li></ul></ul><ul><li>Outline </li></ul><ul><ul><li>Introduction to the Avago’s Gate Driver Optocouplers. </li></ul></ul><ul><ul><li>The typical application </li></ul></ul><ul><li>Contents </li></ul><ul><ul><li>8 pages </li></ul></ul><ul><li>Duration </li></ul><ul><ul><li>5 Minutes </li></ul></ul>
Three Phase Induction Motor with Optocoupler Gate Drivers
HCPL-316J <ul><li>Features </li></ul><ul><li>• 2.5 A maximum peak output current </li></ul><ul><li>• Drive IGBTs up to IC = 150 A, VCE = 1200 V </li></ul><ul><li>• Optically isolated, FAULT status feedback </li></ul><ul><li>• SO-16 package </li></ul><ul><li>• CMOS/TTL compatible </li></ul><ul><li>• 500 ns max. switching speeds </li></ul><ul><li>• “ Soft” IGBT turn-off </li></ul><ul><li>• Integrated fail-safe IGBT protection– Desat (VCE) detection– Under Voltage Lock-Out protection (UVLO) with hysteresis </li></ul><ul><li>• User configurable: inverting, noninverting, auto-reset, auto-shutdown </li></ul><ul><li>• Wide operating VCC range: 15 to 30 Volts </li></ul><ul><li>• -40°C to +100°C operating temperature range </li></ul><ul><li>• 15 kV/μs min. Common Mode Rejection (CMR) at VCM = 1500 V </li></ul><ul><li>• Regulatory approvals: UL, CSA, IEC/EN/DIN EN 60747-5-2 (891 Vpeak Working Voltage) </li></ul>
Example External Blanking Circuit Approach Using Resistor (RB) and Capacitor (CB)
Additional Resource <ul><li>For ordering Avago’s Gate Driver Optocouplers, please call our sales hotline </li></ul><ul><li>For additional inquires contact our technical service hotline </li></ul><ul><li>For more product information go to </li></ul><ul><ul><li>http://www.avagotech.com </li></ul></ul>