Advanced gate drivers for silicon carbide bipolar junction transistors

Abstract

A gate driver circuit comprises a sensor, an amplifier, a regulator, and a gate driver. The sensor is configured to sense a collector-emitter voltage and includes a first resistor and a second resistor connected in series, a high voltage diode connected between the series connected first and second resistors and a first capacitor connected parallel to the second resistor. The amplifier is configured to amplify a sensor output voltage and includes a non-inverting operational amplifier controlled by means of a plurality of resistors, a voltage follower connected to an output terminal of the non-inverting operational amplifier through a first diode and a third resistor connected across the first diode and the voltage follower. The regulator is configured to regulate a regulator output voltage based on an amplifier voltage. The gate driver is configured to connect/disconnect the regulator output voltage to the base terminal of the BJT.

What is claimed is: 
     
         1 . A gate driver circuit, comprising:
 a sensor connected between a collector terminal and an emitter terminal of a bipolar junction transistor (BJT), and configured to sense and measure a collector-emitter voltage V CE ;   a regulator configured to regulate a regulator output voltage based on an amplifier voltage; and   a gate driver connected to the regulator output terminal of the regulator and configured to provide an instantaneous base current based on the collector-emitter voltage of the SiC BJT;   whereby the regulator regulates the voltage of the gate driver to generate the instantaneous proportional base current based on the collector-emitter voltage and monitor the effect of temperature on the DC current gain during the conducting state of the SiC BJT thereby minimizing the driver losses.   
     
     
         2 . The gate driver circuit of  claim 17  wherein the gate driver optimizes the base current based on the collector-emitter voltage by adjusting the supply voltage of the gate driver thereby minimizing the power consumption. 
     
     
         3 . The gate driver circuit of  claim 17  wherein the gate driver output voltage is adjusted during the conducting state of the BJT. 
     
     
         4 . The gate driver circuit of  claim 17  wherein the gate driver optimizes the base current by monitoring the effect of temperature on the DC current gain. 
     
     
         5 . A gate driver circuit, comprising:
 a regulator connected to an amplifier having an amplifier output voltage and configured to regulate a regulator output voltage based on the amplifier output voltage; and   a gate driver connected to a regulator output terminal of the regulator and configured to connect/disconnect the regulator output voltage to a base terminal of the bipolar junction transistor BJT;   wherein the output voltage of the regulator is controlled by an inductor and a capacitor connected at the regulator output terminal.   
     
     
         6 . The gate driver circuit of  claim 6  wherein the amplifier comprises a non-inverting operational amplifier controlled by means of a plurality of resistors, a voltage follower connected to an output terminal of the non-inverting operational amplifier by means of a first diode and a third resistor connected across the voltage follower and the first diode configured to provide the output of the amplifier. 
     
     
         7 . The gate driver circuit of  claim 6  wherein the output voltage of the regulator is controlled by an inductor and a capacitor connected at a regulator output terminal. 
     
     
         8 . The gate driver circuit of  claim 6  wherein a high voltage decoupling diode protects the circuitry comprising the amplifier and the regulator, from high voltage during the OFF state of the BJT. 
     
     
         9 . The gate driver circuit of  claim 6  wherein the amplifier output is used as a voltage reference to the regulator. 
     
     
         10 . The gate driver circuit of  claim 6  further comprising a sensor connected between a collector terminal and an emitter terminal of a bipolar junction transistor (BJT), the sensor configured to sense and measure a collector-emitter voltage V CE    
     
     
         11 . The gate driver circuit of  claim 10  wherein the sensor comprises a first resistor and a second resistor connected in series, a high voltage diode with an anode connected between the series connected first and second resistors and the cathode connected to the collector terminal of the BJT and a first capacitor connected parallel to the second resistor. 
     
     
         12 . The gate driver circuit of  claim 10  wherein the sensor is a high voltage decoupling diode. 
     
     
         13 . The gate driver circuit of  claim 10  wherein the sensor is a Zener diode voltage clamp. 
     
     
         14 . The gate driver circuit of  claim 10  wherein the sensor is configured to measure the collector-emitter voltage V CE  during the ON state of the BJT. 
     
     
         15 . The gate driver circuit of  claim 10  wherein the sensor output voltage is proportional to the collector current of the BJT with an additional offset. 
     
     
         16 . The gate driver circuit of  claim 6  wherein the regulator is a synchronous buck converter. 
     
     
         17 . The gate driver circuit of  claim 6  wherein the regulator provides voltage to the gate driver to provide a continuous supply of base current to maintain the BJT in ON state with minimal conduction losses. 
     
     
         18 . The gate driver circuit of  claim 17  wherein the gate driver optimizes the base current based on the collector-emitter voltage by adjusting the supply voltage of the gate driver thereby minimizing the power consumption. 
     
     
         19 . The gate driver circuit of  claim 17  wherein the gate driver output voltage is adjusted during the conducting state of the BJT. 
     
     
         20 . The gate driver circuit of  claim 17  wherein the gate driver optimizes the base current by monitoring the effect of temperature on the DC current gain.