Charging capacitor during track following in disk drive to provide increased VCM voltage during a seek

A disk drive connectable to a power supply having a fixed DC voltage, the disk drive comprising:

• a voice coil motor (VCM) having a coil;
• a fixed DC voltage power conductor connected to the power supply;
• a controller providing a charging control signal, wherein the charging control signal is at a first level while the disk drive is performing a track following operation and at a second level while the disk drive is performing a track seeking operation;
• a VCM voltage control circuit comprising:
• a first node;
• a second node;
• a ground node;
• a diode coupled between the fixed DC voltage power conductor and the first node to provide the fixed DC voltage to the first node;
• a capacitor having a first terminal coupled to the first node and a second terminal coupled to the second node;
• a first switch coupled between the fixed DC voltage power conductor and the second node and having a first control gate;
• a second switch coupled between the ground node and the second node and having a second control gate;
• and
• a switch control circuit coupled to the first and second control gates, wherein:
• the switch control circuit is responsive to the charging control signal being at the first level to cause the first switch to turn off and the second switch to turn on to charge the capacitor to approximately the fixed DC voltage;
• the switch control circuit is responsive to the charging control signal being at the second level to cause the second switch to turn off and the first switch to turn on to increase the DC voltage of the first node to an increased DC voltage greater than the fixed DC voltage, wherein the diode de-couples the first node from the fixed DC voltage power conductor while the DC voltage of the first node is greater than the fixed DC voltage;
• and
• a voice coil motor driver having switching elements coupled to the first node and the coil of the voice coil motor which are controllable to provide the DC voltage of the first node across the coil.