Marvell International Limited

Marvell Asia Pte., Ltd.

Kuong Hoo, Legal Representative

Siew Yong Chui

Vishnu Kumar

Ying Tian Li

Sakti Pada Rana

Foo Leng Leong

Cheng Yong Teoh

Cheng Yong Toeh

A linear regulator and methods of regulation are provided. In one implementation, a linear regulator is provided. The linear regulator can receive an input voltage, generate an internal bias voltage in response to the received input voltage. The linear regulator can determine if the input voltage meets one or more first criteria and second criteria, and adjust an output voltage based on the internal bias voltage if the input voltage meets the one or more first criteria. The linear regulator also can supply the input voltage directly to the load if the input voltage meets the one or more second criteria. In some implementations, the linear regulator can generate an internal bias voltage that is clamped within a desired operating range if the input voltage meets the one or more first criteria, and adjusts one or more electronic circuits using the internal bias voltage to provide the adjusted output voltage.

Linear regulation for use with electronic circuits

A circuit system and process utilizes back electromotive force (BEMF) voltage to assist in safe power down of devices, such as the read/write head in from low factor disk drives or similar devices. The BEMF voltage from a motor device, such as a spindle motor utilized in a circuit using negative voltage to drive some switches, such as positive channel metal oxide semiconductor ('PMOS') driver transistors, to reduce and/or effectively minimize the on-resistance of the switches while delivering the current from BEMF voltage of the motor to another device, such as a motor that retracts controls a read/write head.

System and process for utilizing back electromotive force in disk drives

A linear regulator is described that includes a mode selection circuit. In one implementation, the mode selection circuit is operable to receive an input voltage and to set an operation mode to one of a first mode or a second mode (e.g., based on a voltage level of the input voltage) so as to generate an output voltage. For example, when the voltage level of the input voltage is within a voltage range, the mode selection circuit can set the first mode as the operation mode to supply the input voltage as the output voltage to a load without voltage regulation. Similarly, when the voltage level of the input voltage is outside the voltage range, the mode selection circuit can set the second mode as the operation mode to regulate the output voltage to the load.

Linear regulator for use with electronic circuits

A linear regulator and methods of regulation are provided. In one implementation, a linear regulator is provided that includes a mode selection circuit operable to determine whether a power source voltage received by the linear regulator exceeds a pre-defined operational range of a load in communication with the linear regulator, and a power switch to directly supply the power source voltage to the load if the power source voltage is within the pre-defined operational range.

A system and method for determining the rotational speed of a motor, such as a three-phase disk drive motor, detects back electromotive force voltage generated during operation of the motor with an automatic pole calibration to minimize or eliminating variations in the wave of a freeze signal. A phase voltage at a winding is compared against a center tap (CT) voltage. Once the phase voltage falls to a specified voltage level, a detect signal is generated. A predetermined time after the detect signal is generated, a freeze signal is generated for freezing at least the circuit associated with the winding.

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Singapore, Singapore

Kuong Hoo, Legal Representative