Abstract: A charging circuit for a bootstrap capacitor comprises a P MOSFET having a body diode and an N channel power MOSFET also having a body diode. The drain of the P MOSFET is coupled to the source of the N channel power MOSFET, and the source of the P MOSFET receives current from a vehicle's battery. The gate of the P MOSFET receives a control signal for turning the P MOSFET either on or off and the drain of the N channel power MOSFET is connected to a bootstrap capacitor The P MOSFET's body diode prevents current flow from the battery to the bootstrap capacitor when the P MOSFET is turned off and the N MOSFET's body diode prevents current flow from the bootstrap capacitor to the battery when the N MOSFET is turned off. The use of a power MOSFET device with its low ON resistance ensures that the capacitor is charged to a sufficiently high voltage even under low battery conditions.

Abstract: A protection circuit and a gate driving circuitry. The protection circuit is for protecting a p-type back-to-back MOS switch. The circuit receives an input driving signal and provides a driving output signal to common gates of the p-type back-to-back MOS switch. The circuit comprises a driving signal insulation switch for disconnecting the common gate of the p-type back-to-back MOS switch from the received input driving signal when the voltage of the common gates is larger than the supply voltage of the circuit. The circuit further comprises a gate source coupling switch for coupling a voltage received at the common source of the p-type back-to-back MOS switch to the common gate if a received voltage at the common sources is larger than a reference voltage Vref.

Abstract: An electronic device is for controlling multiple switching power circuits in a power supply system. Each switching power circuit has a power clock for controlling switching of a supply side switch that enables charging. The device has respective power clock delay units. Each respective power clock delay unit provides a respective power clock at a predetermined delay based on a respective input clock. The respective predetermined delays are chosen so that said switching of respective different supply side switches occurs at respective different points in time. Advantageously the conducted emission in high frequency bands is reduced.

Abstract: A charging circuit for a bootstrap capacitor comprises a P MOSFET having a body diode and an N channel power MOSFET also having a body diode. The drain of the P MOSFET is coupled to the source of the N channel power MOSFET, and the source of the P MOSFET receives current from a vehicle's battery. The gate of the P MOSFET receives a control signal for turning the P MOSFET either on or off and the drain of the N channel power MOSFET is connected to a bootstrap capacitor The P MOSFET's body diode prevents current flow from the battery to the bootstrap capacitor when the P MOSFET is turned off and the N MOSFET's body diode prevents current flow from the bootstrap capacitor to the battery when the N MOSFET is turned off. The use of a power MOSFET device with its low ON resistance ensures that the capacitor is charged to a sufficiently high voltage even under low battery conditions.

Abstract: A protection circuit and a gate driving circuitry. The protection circuit is for protecting a p-type back-to-back MOS switch. The circuit receives an input driving signal and provides a driving output signal to common gates of the p-type back-to-back MOS switch. The circuit comprises a driving signal insulation switch for disconnecting the common gate of the p-type back-to-back MOS switch from the received input driving signal when the voltage of the common gates is larger than the supply voltage of the circuit. The circuit further comprises a gate source coupling switch for coupling a voltage received at the common source of the p-type back-to-back MOS switch to the common gate if a received voltage at the common sources is larger than a reference voltage Vref.

Abstract: A switch arrangement for providing a drive signal at an output comprises a drive switch coupled to the output of the switch arrangement and a regulating element coupled in series between the drive switch and a power supply input of the switch arrangement. The drive switch is operable to provide the drive signal at the output. The switch arrangement is characterized in that the regulating element is coupled in a cascode arrangement with the drive switch such that in operation the regulating element limits the voltage drop across the drive switch to a predetermined level.

Abstract: A drive arrangement for activating a car safety device activation element, such as an air bag, comprises a drive circuit, which is coupled to the car safety device activation element. The drive circuit generates an activation signal which activates the car safety device. The arrangement includes a power supply transistor which is coupled in series with a power supply input of the drive circuit and an energy reservoir such as a capacitor. The arrangement further comprises control means which controls the supply voltage to the drive circuit by controlling the power supply transistor to operate in an active region to provide a voltage drop during activation of the car safety device activation element. Hence, a significant voltage drop and thus energy dissipation may be moved from the drive circuit to the power supply transistor. The drive circuit may therefore be reduced in size and the power supply transistor may be implemented in a cheap technology suitable for energy dissipation.

Abstract: A switch arrangement for providing a drive signal at an output comprises a drive switch coupled to the output of the switch arrangement and a regulating element coupled in series between the drive switch and a power supply input of the switch arrangement. The drive switch is operable to provide the drive signal at the output. The switch arrangement is characterised in that the regulating element is coupled in a cascode arrangement with the drive switch such that in operation the regulating element limits the voltage drop across the drive switch to a predetermined level.

Abstract: A drive arrangement for activating a car safety device activation element, such as an air bag, comprises a drive circuit, which is coupled to the car safety device activation element. The drive circuit generates an activation signal which activates the car safety device. The arrangement includes a power supply transistor which is coupled in series with a power supply input of the drive circuit and an energy reservoir such as a capacitor. The arrangement further comprises control means which controls the supply voltage to the drive circuit by controlling the power supply transistor to operate in an active region to provide a voltage drop during activation of the car safety device activation element. Hence, a significant voltage drop and thus energy dissipation may be moved from the drive circuit to the power supply transistor. The drive circuit may therefore be reduced in size and the power supply transistor may be implemented in a cheap technology suitable for energy dissipation.

Abstract: A drive arrangement for activating a car safety device activation element, such as an air bag, comprises a drive circuit, which is coupled to the car safety device activation element. The drive circuit generates an activation signal which activates the car safety device. The arrangement includes a power supply transistor which is coupled in series with a power supply input of the drive circuit and an energy reservoir such as a capacitor. The arrangement further comprises control means which controls the supply voltage to the drive circuit by controlling the power supply transistor to operate in an active region to provide a voltage drop during activation of the car safety device activation element. Hence, a significant voltage drop and thus energy dissipation may be moved from the drive circuit to the power supply transistor. The drive circuit may therefore be reduced in size and the power supply transistor may be implemented in a cheap technology suitable for energy dissipation.

Abstract: A drive arrangement for activating a car safety device activation element, such as an air bag, comprises a drive circuit, which is coupled to the car safety device activation element. The drive circuit generates an activation signal which activates the car safety device. The arrangement includes a power supply transistor which is coupled in series with a power supply input of the drive circuit and an energy reservoir such as a capacitor. The arrangement further comprises control means which controls the supply voltage to the drive circuit by controlling the power supply transistor to operate in an active region to provide a voltage drop during activation of the car safety device activation element. Hence, a significant voltage drop and thus energy dissipation may be moved from the drive circuit to the power supply transistor. The drive circuit may therefore be reduced in size and the power supply transistor may be implemented in a cheap technology suitable for energy dissipation.