Abstract: A circuit including a level shifting device such as a high voltage MOS device which is turned on to make an output transition, and feedback circuitry which responds to the transition to turn off the level shifting device. A circuit including two n-channel devices and two p-channel devices can sense when current greater than a threshold flows through both devices of one channel type to prevent false output transitions due to rapid changes in offset voltage, or both features can be provided. Level shifting devices can also be connected so none of the devices receives its acknowledge signal from the device to which it provides an acknowledge signal to avoid a standoff between two devices. For each device, the feedback circuitry can distinguish acknowledge signals so a device that stops transmitting in response to a signal that was not an acknowledge signal cam be restarted.

Abstract: 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.

Abstract: A digital level shift circuit includes a level shifting device such as a high voltage MOS device and can also include feedback circuitry. The level shifting device is turned on to make an output transition, and the feedback circuitry obtains a feedback or acknowledge signal indicating that the transition was made. In response, the feedback circuitry turns off the level shifting device, which can reduce power dissipation. A digital level shift circuit that includes two n-channel devices and two p-channel devices can also include sense/prevent circuitry that senses when current greater than a threshold flows through both devices of one channel type and, in response, prevents output transitions from being made, which can avoid false transmissions due to rapid changes in offset voltage. Control circuitry in a digital level shift circuit can include both feedback circuitry and sense-prevent circuitry.

Abstract: An input filter to block noise components of motor phase current used as an input signal for a PWM motor controller. The input filter includes an integration circuit driven by a triggering signal at a frequency which is twice the frequency of operation of the inverter. In one embodiment, a first integrator is coupled directly to the motor drive current signal, and a second integrator is coupled to the motor drive current signal through a circuit which introduces a delay equal to the period of the triggering signal. The difference between the outputs of the integrators is then sampled at the triggering signal frequency. In a second embodiment, a voltage-to-time converter generates a first ramp representing the integral of the phase current signal during a first triggering interval, and a second ramp representing the integral of a reference signal, is subtracted from the value of the first ramp during a second triggering interval until value of integrator output returns to zero.

Abstract: A planar transformer arrangement and method provide isolation between an input signal and an output signal.

Abstract: A circuit for suppressing false operation of a level shift circuit due to a noise transient, the circuit comprising a first transistor coupled to a voltage source of the level shift circuit and being coupled to pass a current when a noise transient is present on the voltage source an output terminal coupled to the first transistor providing as an injected signal a current proportional to the current in the first transistor to at least one level shift transistor of the level shift circuit to prevent false triggering of the level shift circuit due to the noise transient.

Abstract: A digital level shift circuit includes a level shifting device such as a high voltage MOS device and can also include feedback circuitry. The level shifting device is turned on to make an output transition, and the feedback circuitry obtains a feedback or acknowledge signal indicating that the transition was made. In response, the feedback circuitry turns off the level shifting device, which can reduce power dissipation. A digital level shift circuit that includes two n-channel devices and two p-channel devices can also include sense/prevent circuitry that senses when current greater than a threshold flows through both devices of one channel type and, in response, prevents output transitions from being made, which can avoid false transmissions due to rapid changes in offset voltage. Control circuitry in a digital level shift circuit can include both feedback circuitry and sense-prevent circuitry.

Abstract: 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.

Abstract: A circuit for suppressing false operation of a level shift circuit due to a noise transient, the circuit comprising a first transistor coupled to a voltage source of the level shift circuit and being coupled to pass a current when a noise transient is present on said voltage source and an output terminal coupled to the first transistor providing as an injected signal a current proportional to said current in said first transistor to at least one level shift transistor of the level shift circuit to prevent false triggering of the level shift circuit due to the noise transient.

Abstract: A circuit for the controlled recycle without oscillation of a discharge current from an inductive load. The circuit comprises an active element connected, in series with the inductive load, between first and second power supply terminals, and having a control terminal to which a driver circuit is connected. The circuit further includes a recycling regulating circuitry connected to a connection node between the active element and the inductive load, and sensitive to a voltage threshold at the connection node to generate, depending on attainment of that threshold, a power-on signal for application to the control terminal effective to start up recycling of the discharge current through the active element. The circuit further comprises a control circuit for controlling the voltage oscillation at the connection node at the end of the recycling.

Abstract: A reference voltage generator having a dual slope temperature characteristic, for use in an automotive alternator voltage regulator, comprises a bandgap circuit (R1,R2,R3,R4) which generates a voltage (A) having a thermal drift coefficient of zero and a voltage (B) having a non-zero thermal drift coefficient. These voltages are applied to a voltage divider (R5,R6) and a voltage-follower type of circuit (OPA1). A unidirectional conduction amplifier circuit (OPA2) has an input terminal connected to an intermediate point (C) on the voltage divider. A second voltage divider (R7,R8) is connected between the output terminals of the voltage-follower circuit (D) and the amplifier circuit (E) . An intermediate node (F) of the second voltage divider is coupled to an output terminal (VREF) of the generator.