Universal device for DC motor speed control
AssigneeSTMicroelectronics S.r.l.
InventorsSaul Darzy, Jean-Francois Garnier
Life of this patent
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Abstract
There is provided a controller for a DC motor drive transistor which controls a parameter of a motor, the transistor being of PNP or NPN type, and the controller comprising a detection circuit, adapted to determine whether the DC motor drive transistor is of the PNP or NPN type and a driver circuit, adapted to sink current from the PNP transistor if it is determined that a PNP transistor is present, or source current into the NPN transistor if it is determined that an NPN transistor is present.
Claims20
A controller for a DC motor drive transistor which controls a parameter of a motor, the transistor being of PNP or NPN type, the controller comprising:
- a detection circuit, adapted to determine whether the DC motor drive transistor is of the PNP or NPN type;
- and
- a driver circuit, adapted to sink current from the PNP transistor if it is determined that a PNP transistor is present, or source current into the NPN transistor if it is determined that an NPN transistor is present.
A method of controlling a DC motor drive transistor which controls a parameter of a motor, the transistor being of either PNP or NPN type, the method comprising:
- detecting whether the DC motor drive transistor is of the PNP or NPN type;
- and
- configuring a driver circuit to sink current from the PNP transistor if it is determined that a PNP transistor is present, or source current into the NPN transistor if it is determined that an NPN transistor is present.
An integrated circuit chip supporting universal drive capability with respect to a DC motor transistor having an unknown PNP or NPN device type, comprising:
- an input for sensing a voltage derived from a conduction terminal of the DC motor transistor of unknown device type;
- a DC motor transistor driver operable in a first drive mode if the DC motor transistor is of PNP type and operable in a second drive mode if the DC motor transistor is of NPN type;
- a first circuit operable responsive to an initial application of power to the circuit chip to delay sourcing current from the DC motor transistor driver to the DC motor transistor;
- and
- a second circuit coupled to the input and operable, during the delay and based on the sensed voltage, to determine whether the DC motor transistor is of PNP or NPN device type and place the DC motor transistor driver in the first or second drive mode, respectively, before current is sourced from the DC motor transistor driver.
Dependencies are inferred from the claim text.