This invention provides a switch control circuit and a switch circuit. When a main transistor on-time reaches a constant on-time, whether an inductor current reaches an instruction current is detected; if the inductor current fails to reach the instruction current, the main transistor on-time is prolonged; the main transistor is turned off and the auxiliary transistor is turned on until the inductor current reaches the instruction current or exceeds the instruction current by a certain threshold; when the main transistor is turned off and the auxiliary transistor is turned on, the inductor current is detected in real time to check whether the inductor current is smaller than the instruction current, and the auxiliary transistor is turned off and the main transistor is turned on again if yes.

This invention provides a switch control circuit and a switch circuit. When a main transistor on-time reaches a constant on-time, whether an inductor current reaches an instruction current is detected; if the inductor current fails to reach the instruction current, the main transistor on-time is prolonged; the main transistor is turned off and the auxiliary transistor is turned on until the inductor current reaches the instruction current or exceeds the instruction current by a certain threshold; when the main transistor is turned off and the auxiliary transistor is turned on, the inductor current is detected in real time to check whether the inductor current is smaller than the instruction current, and the auxiliary transistor is turned off and the main transistor is turned on again if yes.

A vehicle powertrain includes an IGBT and a gate driver. The IGBT is configured to energize an electric machine. The gate driver is configured to apply an off voltage less than a threshold voltage onto a gate of the IGBT while the IGBT is operating in a saturation mode, and in response to expiration of a delay from a transition from saturation to linear mode, apply a voltage pulse above the off voltage to reduce flyback from the electric machine. The gate driver may be configured to, in response to expiration of a delay from a transition from saturation to linear mode, apply a voltage pulse above the off voltage and below the threshold to reduce flyback from the electric machine.

A vehicle powertrain includes an IGBT and a gate driver. The IGBT is configured to energize an electric machine. The gate driver is configured to apply an off voltage less than a threshold voltage onto a gate of the IGBT while the IGBT is operating in a saturation mode, and in response to expiration of a delay from a transition from saturation to linear mode, apply a voltage pulse above the off voltage to reduce flyback from the electric machine. The gate driver may be configured to, in response to expiration of a delay from a transition from saturation to linear mode, apply a voltage pulse above the off voltage and below the threshold to reduce flyback from the electric machine.

Disclosed examples provide DC-DC converters and control circuits to provide high and low-side driver signals and to selectively adjust a delay time between a low-side switching device turning off and a high-side switching device turning on according to a comparator signal, including a clocked comparator circuit referenced to a switching node to sample the voltage across the high-side switching device in response to a first edge of the high-side driver signal, and to generate the comparator signal indicating a polarity of the sampled high-side switch voltage to facilitate zero voltage switching of the high-side switching device.

Disclosed examples provide DC-DC converters and control circuits to provide high and low-side driver signals and to selectively adjust a delay time between a low-side switching device turning off and a high-side switching device turning on according to a comparator signal, including a clocked comparator circuit referenced to a switching node to sample the voltage across the high-side switching device in response to a first edge of the high-side driver signal, and to generate the comparator signal indicating a polarity of the sampled high-side switch voltage to facilitate zero voltage switching of the high-side switching device.

A signal multiplexer according to the present embodiment has a configuration sufficiently capable of accelerating a data rate. The signal multiplexer includes M number of front units and a rear unit. An m-th front unit A.sub.m outputs an output signal corresponding to an m-th input signal I.sub.m when both the control signal C.sub.m and the control signal C.sub.n are significant levels, and outputs an output signal having a fixed level when at least either one of the control signal C.sub.m or the control signal C.sub.n is an non-significant level. A rear unit B receives signals from the front units, and outputs a signal having a different signal level in a case in which all the output signals from the front units are the same level or in the other case.

A signal multiplexer according to the present embodiment has a configuration sufficiently capable of accelerating a data rate. The signal multiplexer includes M number of front units and a rear unit. An m-th front unit A.sub.m outputs an output signal corresponding to an m-th input signal I.sub.m when both the control signal C.sub.m and the control signal C.sub.n are significant levels, and outputs an output signal having a fixed level when at least either one of the control signal C.sub.m or the control signal C.sub.n is an non-significant level. A rear unit B receives signals from the front units, and outputs a signal having a different signal level in a case in which all the output signals from the front units are the same level or in the other case.

A temperature protection device includes temperature detection devices detecting the temperatures of switching elements and a control device controlling the switching elements. The control device stops driving of a first switching element the temperature of which rises to an overheat detection temperature and resumes the driving of the first switching element when the temperature of the first switching element drops to a return temperature. The control device controls timing of resuming the driving of the first switching element so that an undriven time period of the first switching element is longer in a case where at least one of the switching elements other than the first switching element is in a high load state when the temperature of the first switching element reaches the overheat detection temperature than that in a case where all the switching elements other than the first switching element are in a low load state.

A temperature protection device includes temperature detection devices detecting the temperatures of switching elements and a control device controlling the switching elements. The control device stops driving of a first switching element the temperature of which rises to an overheat detection temperature and resumes the driving of the first switching element when the temperature of the first switching element drops to a return temperature. The control device controls timing of resuming the driving of the first switching element so that an undriven time period of the first switching element is longer in a case where at least one of the switching elements other than the first switching element is in a high load state when the temperature of the first switching element reaches the overheat detection temperature than that in a case where all the switching elements other than the first switching element are in a low load state.