Disc drive power management system

A semiconductor integrated circuit disc drive power management system comprising:

• a) three spindle-motor contact pads to which a three phase DC spindle motor may be connected, and two actuator-motor contact pads to which an actuator motor may be connected;
• b) a pair of DC-voltage busses;
• c) three pairs of spindle-motor drive transistors, each of said pair transistors being connected in a series circuit that is connected directly across said pair of DC-voltage busses, the junction between said pair of spindle-motor drive transistors connected respectively to said three spindle-motor contact pads;
• d) six rectifier diodes each connected, respectively, directly across one of the six spindle-motor drive transistors in the same polarity with respect to said pair of DC-voltage busses;
• e) an actuator power amplifier connected directly between said DC-voltage busses, and having two output conductors connected to said two actuator-motor contact pads;
• and
• f) two DC-supply-voltage terminals adapted for connection to a source of DC voltage, and a connection between said DC-supply-voltage terminals and said pair of DC-voltage busses;
• and
• g) said DC-supply-voltage terminals-to-busses connection comprises of a transistor switch means for rendering said connection conducting when the voltage appearing across said two DC-supply-voltage terminals is within a predetermined nominal range, and for rendering said connection non-conducting when the voltage appearing across said two DC-supply-voltage terminals falls below said range.

A disc drive power management system comprising:

• a) a pair of DC-voltage busses;
• b) three spindle-motor terminals to which a three phase DC spindle motor may be connected, and two actuator-motor terminals to which an actuator motor may be connected;
• d) a three phase spindle-motor power amplifier connected directly between said pair of DC-voltage busses, said-spindle motor power amplifier comprising three pairs of field effect driver transistors and having a three phase output connected to said three spindle-motor terminals;
• e) an actuator-motor power amplifier connected directly between said DC-voltage busses and having an output connected to said actuator-motor terminals;
• f) two DC-supply-voltage terminals to which a DC voltage source may be connected;
• g) a transistor switch means, said pair of DC-voltage busses being connected to said DC-supply-voltage terminals through said transistor switch means, said transistor switch means being for turning on and energizing said busses when the voltage appearing across said two DC-supply-voltage terminals is within a predetermined nominal range, and for turning off and de-energizing said busses when the voltage appearing across said two DC-supply-voltage terminals falls below said range;
• and
• h) six operational amplifiers each comprising one and another differential inputs, and a single ended output, each of said operational amplifiers associated respectively with one of said six field effect driver transistors, each of said driver transistors having a source and a drain, and having a gate connected to said switch means, one of said source and drain being connected to the channel region and to said one input of said associated operational amplifier, the other of said source and drain connected to said other input of said associated operational amplifier,
• said switch means being additionally for during a period when said busses are energized, connecting said driver transistor gates to the outputs of a conventional three phase commutator circuit that may be connected to said switch means, and for during a period when said busses are not energized connecting each said driver transistor gate to said associated operational amplifier output to convert each of said six field effect driver transistors to a simulated FET diode during periods when said busses are de-energized.

A disc drive power management system comprising:

• a) a pair of DC-voltage busses;
• b) three spindle-motor terminals to which a three phase DC spindle motor may be connected, and two actuator-motor terminals to which an actuator motor may be connected;
• d) a three phase spindle-motor power amplifier connected directly between said pair of DC-voltage busses, said-spindle motor power amplifier comprising three pairs of field effect driver transistors and having a three phase output connected to said three spindle-motor terminals;
• e) an actuator-motor power amplifier connected directly between said DC-voltage busses and having an output connected to said actuator-motor terminals;
• f) two DC-supply-voltage terminals to which a DC voltage source may be connected;
• g) a transistor switch means, said pair of DC-voltage busses being connected to said DC-supply-voltage terminals through said transistor switch means, said transistor switch means being for turning on and energizing said busses when the voltage appearing across said two DC-supply-voltage terminals is within a predetermined nominal range, and for turning off and de-energizing said busses when the voltage appearing across said two DC-supply-voltage terminals falls below said rage;
• h) at least two operational amplifiers each comprising a first and a second differential inputs, and a single ended output, said two operational amplifiers associated respectively with the two driver transistors making up one of said driver transistor pairs, each of said one-pair driver transistors having a source and a drain, and having a gate connected to said switch means, one of said source and drain being connected to the channel region and to said one input of said associated operational amplifier, the other of said source and drain connected to said other input of said associated operational amplifier,
• said switch means being additionally for during a period when said busses are energized, connecting said driver transistor gates to the outputs of a conventional three phase commutator circuit that may be connected to said switch means, and for during a period when said busses are not energized connecting each said driver transistor gate to said associated operational amplifier output to convert each of said six field effect driver transistors to a simulated FET diode during periods when said busses are de-energized.