Bridge output circuit, motor driver device and semiconductor device

A bridge output circuit that receives a rectangular wave input signal and supplies an output voltage corresponding to the rectangular wave input signal to a load connected to an output terminal, comprising:

• a voltage-controlled first transistor provided between a first power supply terminal to which a predetermined power supply voltage is applied and the output terminal;
• a voltage-controlled second transistor provided between the output terminal and a second power supply terminal having a potential lower than the potential of the first power supply terminal;
• a first OFF detection circuit configured to detect whether or not the voltage-controlled first transistor is in an OFF state based on a gate voltage of the voltage-controlled first transistor;
• a second OFF detection circuit configured to detect whether or not the voltage-controlled second transistor is in an OFF state based on a gate voltage of the voltage-controlled second transistor;
• and
• an output control circuit configured to perform a first sink transition operation of turning off the voltage-controlled first transistor and then turning on the voltage-controlled second transistor in response to a first signal change in the rectangular wave input signal based on the rectangular wave input signal, a detection result of the first OFF detection circuit and a detection result of the second OFF detection circuit in a sink state in which a current flows from the load toward a connection node between the voltage-controlled first transistor and the voltage-controlled second transistor via the output terminal, and then to perform a second sink transition operation of turning off the voltage-controlled second transistor and then turning on the voltage-controlled first transistor in response to a second signal change in the rectangular wave input signal,
• wherein the output control circuit acquires an analog signal according to a length of dead time in which both the voltage-controlled first transistor and the voltage-controlled second transistor are turned off during the first sink transition operation, and then starts the second sink transition operation after waiting for a lapse of time based on the acquired analog signal when the second signal change occurs in the rectangular wave input signal.

A bridge output circuit that receives a rectangular wave input signal and supplies an output voltage corresponding to the rectangular wave input signal to a load connected to an output terminal, comprising:

• a voltage-controlled first transistor provided between a first power supply terminal to which a predetermined power supply voltage is applied and the output terminal;
• a voltage-controlled second transistor provided between the output terminal and a second power supply terminal having a potential lower than the potential of the first power supply terminal;
• a first OFF detection circuit configured to detect whether or not the voltage-controlled first transistor is in an OFF state based on a gate voltage of the voltage-controlled first transistor;
• a second OFF detection circuit configured to detect whether or not the voltage-controlled second transistor is in an OFF state based on a gate voltage of the voltage-controlled second transistor;
• a voltage comparison circuit configured to compare the output voltage with a plurality of comparison voltages;
• and
• an output control circuit configured to control an ON/OFF state of the voltage-controlled first transistor and the voltage-controlled second transistor based on the rectangular wave input signal, a detection result of the first OFF detection circuit and a detection result of the second OFF detection circuit,
• wherein the output control circuit performs a first source transition operation of turning off the voltage-controlled second transistor and then turning on the voltage-controlled first transistor in response to a first signal change in the rectangular wave input signal in a source state in which a current flows from a connection node between the voltage-controlled first transistor and the voltage-controlled second transistor toward the load via the output terminal, and then performs a second source transition operation of turning off the voltage-controlled first transistor and then turning on the voltage-controlled second transistor in response to a second signal change in the rectangular wave input signal,
• wherein the output control circuit performs a first sink transition operation of turning off the voltage-controlled first transistor and then turning on the voltage-controlled second transistor in response to the second signal change in the rectangular wave input signal in a sink state in which a current flows from the load toward the connection node via the output terminal, and then performs a second sink transition operation of turning off the voltage-controlled second transistor and then turning on the voltage-controlled first transistor in response to the first signal change in the rectangular wave input signal,
• wherein the output control circuit includes a determination circuit that determines whether the output control circuit is in the source state or the sink state based on the detection result of the first OFF detection circuit, the detection result of the second OFF detection circuit and a comparison result of the voltage comparison circuit,
• wherein, upon determining by the determination circuit that the output control circuit is in the source state, the output control circuit acquires a first analog signal according to a length of dead time in which both the voltage-controlled first transistor and the voltage-controlled second transistor are turned off during the first source transition operation, and then starts the second source transition operation after waiting for a lapse of time based on the acquired first analog signal when the second signal change occurs in the rectangular wave input signal, and
• wherein, upon determining by the determination circuit that the output control circuit is in the sink state, the output control circuit acquires a second analog signal according to a length of dead time in which both the voltage-controlled first transistor and the voltage-controlled second transistor are turned off during the first sink transition operation, and then starts the second sink transition operation after waiting for a lapse of time based on the acquired second analog signal when the first signal change occurs in the rectangular wave input signal.