Power supply voltage adjustment circuit and information storage device

An information storage device comprising:

• a head configured to read data from an information recording medium or to write data to the information recording medium;
• a read channel configured to exchange information with the head;
• a power supply module configured to supply a voltage to the read channel;
• and
• a power voltage adjustment circuit configured to adjust a target control value of the supply voltage, the power voltage adjustment circuit comprising
• a determination module configured to determine whether the head is positioned on a data area addressed by a command received from a host based on a relationship between a position of the head and the command;
• and
• a voltage controller configured to adjust the target control value of the power voltage according to a duration from a time point when a servo mark on the information recording medium is detected, when the head is determined not to be positioned on the data area addressed by the command.