Abstract: A dynamic voltage compensation circuit suitable for performing voltage compensation between an electronic device and a multimedia device, and includes a current detection unit, a calculation module and a voltage output unit. The current detection unit is configured to obtain the output current of the electronic device outputting the multimedia device from the bus power terminal. The calculation module is configured to receive the output current and an ideal reference voltage, execute a voltage compensation algorithm to calculate a predetermined output voltage based on the output current, the ideal reference voltage, and a compensation coefficient, and generate a control signal according to the predetermined output voltage. The voltage output unit is configured to receive a control signal, and is controlled by the control signal to generate a compensated output voltage and output it to a bus power terminal.

Abstract: A chip includes a receiving, a transmission, a control, and a switch circuit. The receiving circuit is operated at a first voltage and receives a first data. The transmission circuit is operated at the first voltage. Under general mode, the control circuit is operated at a second voltage and generates a second data to the transmission circuit according to the first data. The control circuit includes a first clock source configured to provide a first clock under general mode. The control circuit is operated according to the first clock. Under general mode, the switch circuit is operated at the first voltage, and controls the second voltage to pause the second voltage supplying to the control circuit to enter sleep mode. Under sleep mode, the switch circuit controls the supply of the second voltage: to the control circuit according to the first data to return to general mode.

Abstract: A chip includes a receiving, a transmission, a control, and a switch circuit. The receiving circuit is operated at a first voltage and receives a first data. The transmission circuit is operated at the first voltage. Under general mode, the control circuit is operated at a second voltage and generates a second data to the transmission circuit according to the first data. The control circuit includes a first clock source configured to provide a first clock under general mode. The control circuit is operated according to the first clock. Under general mode, the switch circuit is operated at the first voltage, and controls the second voltage to pause the second voltage supplying to the control circuit to enter sleep mode. Under sleep mode, the switch circuit controls the supply of the second voltage to the control circuit according to the first data to return to general mode.

Abstract: A dynamic voltage compensation circuit suitable for performing voltage compensation between an electronic device and a multimedia device, and includes a current detection unit, a calculation module and a voltage output unit. The current detection unit is configured to obtain the output current of the electronic device outputting the multimedia device from the bus power terminal. The calculation module is configured to receive the output current and an ideal reference voltage, execute a voltage compensation algorithm to calculate a predetermined output voltage based on the output current, the ideal reference voltage, and a compensation coefficient, and generate a control signal according to the predetermined output voltage. The voltage output unit is configured to receive a control signal, and is controlled by the control signal to generate a compensated output voltage and output it to a bus power terminal.

Abstract: A sensorless driving method for a brushless DC motor is provided. The time for the motor to rotate an electrical angle 60° is obtained by alternatively counting the occurrences of zero crossings with two counters and comparing the counted values, and the motor is delayed an electrical angle of 30°, by which a precise commutating time is obtained. The driving method provides a mask-based phase shift digital detection mechanism for effectively detecting true zero-crossing points. The driving method further provides an inhabitation mechanism with the function of soft-switch for inhibiting noise caused by transistor switching. By using these two counters, the time for the motor to rotate two electrical angles 30°??? and 30°+?? are obtained and stored in two registers. The time period before and after the commutating point is added into a pulse width modulation (PWM) signal to reduce the noise and vibration.

Abstract: A sensorless driving method for a brushless DC motor is provided. The time for the motor to rotate an electrical angle 60° is obtained by alternatively counting the occurrences of zero crossings with two counters and comparing the counted values, and the motor is delayed an electrical angle of 30°, by which a precise commutating time is obtained. The driving method provides a mask-based phase shift digital detection mechanism for effectively detecting true zero-crossing points. The driving method further provides an inhabitation mechanism with the function of soft-switch for inhibiting noise caused by transistor switching. By using these two counters, the time for the motor to rotate two electrical angles 30°??? and 30°+?? are obtained and stored in two registers. The time period before and after the commutating point is added into a pulse width modulation (PWM) signal to reduce the noise and vibration.