International Rectifier Corporation

Giovanni Galli

Massimo Grasso

Toshio Takahashi

Marco Giandalia

Cesare Bocchiola

Christian Locatelli

Andrea Merello

A driver integrated circuit for driving at least one high voltage half bridge stage. The driver including a filter circuit for filtering a signal provided to the half bridge stage, a minimum pulse width of the signal being near a constant time of the filter, wherein the filter circuit prevents distortions introduced when the signal is at its minimum pulse width from being passed to the half bridge stage.

Half bridge driver input filter

A temperature sensor circuit in accordance with an embodiment of the present invention includes a temperature sensing element operable to provide a temperature voltage that is linearly related to the absolute temperature of the circuit. The temperature sensing element includes a first bi-polar junction transistor and a second bipolar junction transistor connected between a supply voltage and a common ground, wherein the base of first bipolar junction transistor is connected to the base of the second bipolar junction transistor, a first resistor connected between an emitter of the first bipolar junction transistor and the common ground and a second resistor connected between the common ground and a first node, wherein the temperature voltage is provided to the first node across the second resistor. The temperature sensor circuit also includes a current supply element operable to supply a common current to a collector of the first bipolar junction transistor, the second bipolar junction transistor and to the second resistor, respectively, an early voltage element operable to compensate for variations in voltage, a base current element operable to provide a steady base current to the bases of the first and second bipolar junction transistors, a channel modulation element operable to compensate for channel modulation and a leakage element operable to compensate for epi-substrate leakage between the circuit and a substrate on which it is formed.

Precision temperature sensor

A safety circuit for providing protection against failures that impact safety of an inverter circuit driving a Permanent Magnet Synchronous Motor (PMSM) including high and low side switches connected in a bridge and driven by a gate driver circuit during operation of the PMSM in a field weakening mode, the gate driver circuit including stages for driving the high and low side switches, the safety circuit comprising a main power supply and a back-up power supply for supplying voltage to the gate driver circuit driving the switches of the bridge of the inverter circuit, wherein if the main power supply fails to deliver adequate power to the gate driver circuit, the back-up power supply provides power to the gate driver circuit to allow the gate driver circuit to turn ON the low side switches and turn OFF the high side switches.

Protection circuit for permanent magnet synchronous motor in field weakening operation

A circuit for protecting against controller failure wherein the controller provides control signals for controlling a DC to AC inverter fed by a DC bus and driving a permanent magnet motor, the circuit comprising a first circuit for monitoring the DC bus voltage and, in the event the DC bus voltage exceeds a first threshold due to a counter EMF generated by the motor, for producing a signal to the controller to provide a switch state to the inverter whereby the counter EMF is dissipated substantially in a motor circuit resistance of the permanent magnet motor as a result of a short circuit condition provided by the switch state of the inverter, thereby preventing the DC bus voltage of the inverter from exceeding the first threshold and causing the permanent magnet motor speed to be reduced.

Safety interlock and protection circuit for permanent magnet motor drive

A gate drive integrated circuit for switching power transistors using an external controller includes a gate driving capability and low quiescent current and allows use of a bootstrap supply technique for providing the logic supply voltage. The gate driver integrated circuit detects power transistor desaturation, protecting a desaturated transistor from transient over voltages by smoothly turning off the desaturated transistor via a soft shutdown sequence. A fault control circuit of the gate driver integrated circuit manages protection of supply under-voltage and transistor desaturation and is capable of communicating with a plurality of gate driver integrated circuits in a multi-phase system using a dedicated local network.

Half-bridge high voltage gate driver providing protection of a transistor

A power control circuit includes sensing circuitry for sensing information about operation of a power device such as an IGBT or other power FET. The sensing circuitry receives a sense input signal from the power device through a gating device such as a diode. The power control circuit also includes active impedance circuitry for preventing the sense input signal from including spurious information received from the gating device. For example, if the gating device is a diode across which negative spikes can be capacitively coupled, the active impedance circuitry can prevent the negative spikes from reaching the sensing circuitry when the diode is off. The active impedance circuitry can take the form of a transistor connected between a power supply and a sensing node. The active impedance device can be switched on by a comparator when the voltage across the power device exceeds a reference voltage, indicating the power device is off. Alternatively, the active impedance device can be controlled by a comparator in the sensing circuitry that provides an output that similarly indicates whether the power device is on or off. The sensing circuitry and active impedance circuitry can be implemented on an integrated circuit.

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Manhattan Beach, CA, United States of America

Giovanni Galli