Method and circuitry for high voltage application with mosfet technology

A disk drive apparatus capable of writing data to at least one disk, comprising:

• at least one write heads capable of writing data to at least the one disk;
• at least one write driver, at least the one write driver coupled to at least the one write head, and enabling/disabling writing of data to at least the one disk;
• at least one switch circuit, at least the one switch circuit coupled to at least the one write driver and switching on/off at least the one write driver, at least the one switch circuit capable of providing an output voltage higher than a breakdown voltage of a FET device to switch on at least the one write driver and providing proximate zero voltage to switch off at least the one write driver, the switch circuit comprising:
• the FET device which has a terminal being an output of at least the one switch circuit, and a bipolar device controlling bias to the FET device;
• and
• wherein when at least the one switch circuit switches on at least the one write driver, data is written on at least the one disk.

A switch circuit capable of providing an output voltage between ground and a first power supply voltage which is higher than a predetermined voltage, comprising:

• a first resistor having a first end and a second end coupled to the ground;
• at least a first PFET and a second PFET, the first PFET having a source coupled to a first power supply and a drain coupled to a source of the second PFET, the second PFET having a drain coupled to the first end of the first resistor, the first power supply providing the first power supply voltage;
• a second resistor having a first end and a second end;
• at least one NFET having a source coupled to the ground and a drain coupled to the first end of the second resistor;
• a bipolar transistor having an emitter coupled to the second end of the second resistor;
• a first diode having a first end and a second end, the first end of the first diode coupled to a collector of the bipolar transistor;
• a second diode coupled between the first end of the first diode and a gate of the second PFET;
• a third diode coupled between the second diode and the source of the second PFET;
• a third resistor coupled between a second power supply and the gate of the second PFET, the second power supply providing the predetermined voltage;
• a fourth resistor coupled between the second power supply and the base of the bipolar transistor;
• a fifth resistor coupled between the base of the bipolar transistor and the drain of the at least one NFET;
• a sixth resistor coupled between the second end of the first diode and the first power supply;
• a seventh resistor coupled between the second end of the first diode and the gate of the first PFET;
• an input of the switch circuit coupled to a gate of the at least one NFET;
• and
• an output of the switch circuit coupled to a drain of the second PFET.

A method of writing data in a disk drive apparatus having at least one write driver coupled to at least one write head for writing data to at least one disk, at least the one write driver coupled to a switch circuit having a FET device and a bipolar device controlling bias to the FET device, comprising the steps of:

• selecting one of at least the one write driver for writing on a track position of one of at least the one disk;
• sending a write signal to the respective switch circuit;
• switching on the respective switch circuit which provides an output voltage higher than a breakdown voltage of the FET device and providing zero voltage when the switch circuit switches off;
• and
• writing data on the respective disk via the respective write head.

A switch circuit capable of providing an output voltage between ground and a power supply voltage which is higher than a predetermined voltage, comprising:

• a first FET device;
• a second FET device coupled to the first FET device in series between the ground and the first power supply voltage, the second FET having a drain being an output of the switch circuit;
• a first diode coupled to a gate of the first FET device;
• a second diode coupled between a source and a gate of the second FET device;
• a third diode coupled between the first diode and the second diode;
• a bipolar transistor having a collector coupled to both the first and third diodes;
• a third FET device coupled between an emitter of the bipolar transistor and the ground, the third FET device having a gate being an input of the switch circuit;
• and
• wherein the bipolar transistor controls voltage bias to the diodes and the first and second FET devices.