Aimtron Technology Corp.

Global Mixed-Mode Technology Inc.

Guang-Nan Tzeng

Tien-Tzu Chen

Chi-Yang Chen

Yung-Chih Chen

Rong-Chin Lee

Feng-Rurng Juang

Tien Tzu Chen

Wei-Yu Chen

Ya-Der Tain

Yu-Ming Tsai

A motor controller comprises a switch circuit, a control circuit, and a function pin. The switch circuit is coupled to a motor for driving the motor. The control circuit generates a plurality of control signals to control the switch circuit. The function pin is coupled to the control circuit for receiving a function signal. The function signal is configured to inform the motor controller to execute a braking function. The braking function enables a braking time to be a variable value.

Motor controller

A motor controller is used for driving a motor, where the motor has a motor coil. The motor controller comprises a switch circuit, a control unit, and a phase detecting unit. The switch circuit is configured to supply a coil current to the motor coil. The control unit generates a plurality of control signals to control the switch circuit. The phase detecting unit generates a phase signal to the control unit. When the phase signal is changed from a first level to a second level, the motor controller starts a phase delay mechanism to reduce the risk of reverse flow of the coil current. The phase delay mechanism lasts a time. The motor controller may utilize the phase delay mechanism in a start mode or a normal operation mode.

A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit is configured to generate a plurality of control signals to control the switch circuit. The motor controller sequentially determines a first phase, a second phase, a third phase, and a fourth phase based on a rotation direction. When the motor controller is in the first phase and the motor controller is unable to detect a phase switching time point within a starting time, the motor controller switches from the first phase to the second phase, the third phase, or the fourth phase. The motor controller is configured to increase a success rate of starting the motor.

A motor unit comprises a motor controller, a motor, and a Hall sensor, where the motor controller is used for driving the motor. The motor controller comprises a switch circuit, a control unit, a phase signal generating unit, and an operational amplifier. The control unit generates a plurality of control signals to control the switch circuit. The motor comprises a rotor, a silicon steel plate, and a coil. To increase a success rate of starting a forward rotation, the silicon steel plate may have an asymmetrical structure, such that a fan blade is inclined to a forward rotation direction in a still state. When a Hall voltage is zero, the motor controller may start the motor and switch phases.

Motor unit

A motor controller comprises a switch circuit, a driving circuit, and a pulse width modulation circuit. The switch circuit is coupled to a three-phase motor for driving the three-phase motor. The driving circuit generates a plurality of control signals to control the switch circuit. When the three-phase motor is operated in a start state, the motor controller may enable an electric period to be divided into more floating phase time intervals for switching phases, so as to increase the success rate of phase switching. When the three-phase motor is operated in a stable state, the motor controller may enable the electric period to be divided into less floating phase time intervals for switching phases, so as to reduce the noise and vibration of the three-phase motor.

A motor controller used for driving a motor is provided. The motor controller includes a driving circuit, a control unit, an operational amplifier, a comparator, an inverter, a multiplexer, a first resistor, and a second resistor. The first and second resistors are mounted on a printed circuit board. By changing the resistance of the first resistor and the resistance of the second resistor, it is capable of changing the driving direction of the motor.

An overvoltage protection circuit which can be applied to a motor controller is provided. The overvoltage protection circuit comprises a voltage controller, a comparator, and a switching circuit so as to prevent damage to a driving circuit. The driving circuit is configured to supply a driving current to a motor coil.

Overvoltage protection circuit

A PFM control circuit generates a pulse control signal for controlling a switching regulator to convert an input voltage into an output voltage. The pulse control signal has a plurality of switch cycles, each of which consists of an ON-time and an OFF-time. The ON-time is applied to turn on a switching circuit of the switching regulator while the OFF-time is applied to turn off the switching circuit. A current detection signal is representative of a current flowing through an inductive device of the switching regulator. The ON-time is prolonged in accordance with an increase of a maximum of the current detection signal. A voltage detection signal is representative of the output voltage. The OFF-time is prolonged in accordance with a reduction of a falling rate of the voltage detection signal.

PFM control circuit for DC regulator

A switching circuit operates with a first operating state and a second operating state. During the first operating state, the switching circuit allows a switching current to linearly increase. During the second operating state, the switching circuit allows the switching current to linearly decrease. A control circuit is coupled to the switching circuit for controlling the switching circuit to operate with the first operating state or the second operating state. A setting circuit generates a threshold signal for the control circuit to ensure that during the first operating state the switching current linearly increases to become higher than or equal to a current value set by the threshold signal. Thereby, the switching current is prevented from linearly decreasing to reverse polarity during the second operating state.

Switching voltage regulator operating without a discontinuous mode

An input switching unit selectively couples a first terminal of an inductor with an input voltage and a ground potential. An output switching unit selectively couples a second terminal of the inductor with an output voltage and the ground potential. A first pulse generating circuit generates a first pulse signal with a first duty ratio, which is modulated in response to the output voltage. A second pulse generating circuit generates a second pulse signal with a second pulse signal with a second duty ratio, which is a constant larger than zero and smaller than one. When the first duty ratio is larger than a predetermined threshold duty ratio, a mode control circuit applies the first pulse signal to control one of the input switching unit and the output switching unit and applies the second pulse signal to control another of the input switching unit and the output switching unit.

Buck-boost voltage converter

In a pulse frequency modulated (PFM) voltage regulator, a PFM switching signal is provided for converting a DC voltage source to an output voltage. The output voltage is detected. When the output voltage is lower than a predetermined target voltage, a duty cycle of the PFM switching signal is reduced. For example, a minimum OFF-time of the PFM switching signal may be prolonged or a constant ON-time of the PFM switching signal may be shortened. In other words, a period of delivering energy to a capacitor from an inductor may be prolonged or a period of storing energy in the inductor may be shortened. Therefore, a ripple of the output voltage is effectively reduced when the PFM voltage regulator is operated in a heavy loading condition.

Method of reducing a ripple of a heavy loading pulse frequency modulated voltage regulator

A voltage detection unit generates a detection voltage signal representative of a potential difference caused by a current to be detected. A reference current generation unit generates a first reference current and a second reference current having a linear relationship therebetween. In response to the detection voltage signal and the first reference current, a transfer unit determines a first operation voltage. Furthermore, the transfer unit determines a second operation voltage and a transfer current in response to the first operation voltage and the second reference current. The second operation voltage is substantially equal to the first operation voltage. A detection current signal having a linear relationship with the current to be detected is generated through subtracting at least the second reference current from the transfer current.

Current sensing circuit

A Hall sensing circuit generates a positional detection signal representative of a positional relationship between a rotor and a phase coil of a motor. A signal synthesizing circuit transforms the positional detection signal to a driving signal. Based on a comparison of the driving signal and a high-frequency reference signal, a pulse signal is generated for controlling a switching circuit to drive the motor. A current error signal is supplied through feedback to adjust a relative relationship between an amplitude of the drive signal and an amplitude of the high-frequency reference signal, thereby changing a duty ratio of the pulse signal. A duty-ratio limiting circuit is provided to limit the duty ratio of the pulse signal for ensuring a reliable rotation of the motor.

Brushless motor drive device

A charge pump is driven by at least one clock signal, for converting a supply voltage source into a pumping voltage. The pumping voltage is a function of an amplitude of the at least one clock signal such that an absolute value of the pumping voltage is larger when the amplitude of the at least one clock signal is larger. The amplitude of the at least one clock signal is so modulated as to gradually change from an activation value during an amplitude modulation period. The amplitude modulation period lasts longer than a period of the at least one clock signal by one or more metric orders. The charge pump is activated by the at least one clock signal with the amplitude of the activation value. Thereafter, the charge pump is controlled in such a way that the absolute value of the pumping voltage gradually changes along with the modulation of the amplitude of the at least one clock signal.

Soft-start charge pump circuit

First and second clocks are applied to first and second capacitors, respectively. First and second former-stage clocks are applied to first and second former-stage capacitors, respectively. A first switch couples the second former-stage capacitor with the first capacitor. A second switch couples the first former-stage capacitor with the second capacitor. A first reverse current preventing circuit couples a control electrode of the first switch alternately with the second capacitor and the second former-stage capacitor. A second reverse current preventing circuit couples a control electrode of the second switch alternately with the first capacitor and the first former-stage capacitor. Falling edges of the first and second clocks occur earlier than falling edges of the first and second former-stage clocks, respectively. Rising edges of the first and second former-stage clocks occur earlier than rising edges of the first and second clocks, respectively.

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Hsinchu, Taiwan

Guang-Nan Tzeng