Ami Semiconductor Belgium Bvba

Jan Plojhar

Lucas Emiel Elie Vander Voorde

A regulated mirror current source circuit has an output transistor, a regulator for controlling the output circuit, and a current mirror having two or more current paths. The first path of the mirror is coupled in series with a current path of the output circuit, and the second path is coupled to the regulator, to provide feedback. The feedback can provide better precision, or reduced component area. The circuit can include cascode transistors, and the regulator can have integral control. The output transistor gate-source voltage is overdriven to reduce 'on' resistance of the output transistor. When the output transistor is a high voltage transistor, its area can be reduced without sacrificing compliance.

Regulated current mirror

A method for detecting rotation of a rotor of a multiple phase motor with bipolar drive is described, excluding a three-phase motor with bipolar drive with star connected coils or motor stator windings. The motor has at least a first and a second energizable motor stator winding. A voltage is sequentially and alternately sensed on the first and the second motor stator winding at or near the end of a period of a non-energised state thereof. An apparatus for detecting rotor speed is also provided.

Device and method for detecting rotor speed of a multiple phase motor with bipolar drive

A PWM controller for a bridge driver circuit for controlling current in an inductive load such as a motor, can set the driver into a forward mode, a slow decay mode or a fast decay mode, and can switch from slow decay mode into forward mode or into fast decay mode for the duration of pulses at controlled time intervals to provide pulse width modulated control of the current. This is a simpler control scheme avoiding complex switching schemes related to mixed mode decay. By using a controlled PWM frequency, it is easier to avoid the problems of variable frequency such as increased heat dissipation or acoustic noise generation. It can have a selector for selecting top or bottom sense switching, enabling a wider range of stable PWM duty-cycles to be used (e.g. 0% to 100%), which is useful to compensate for Back emf influence on coil-drive.

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Mokra-Horakov, Czechia

Jan Plojhar