Patent ID: 7639592

Claim:
An interface for an optical pick-up head configured to output one of a reading voltage or a writing voltage, said interface comprising: a first P-TYPE Metal Oxide Semiconductor device (PMOS) comprising a first source/drain, a first PMOS gate and a substrate, wherein said first source/drain is configured to receive one of said reading voltage or said writing voltage, and said first PMOS gate is configured to receive a gate voltage for turning on a path between said first source/drain of said first PMOS and a second source/drain of said first PMOS, and said substrate is configured to receive a control voltage; a boost circuit connectable with said first PMOS gate and configured to boost said gate voltage greater than said control voltage and turn off a path between said first source/drain and said second source/drain so as to block said writing voltage; and a sample and hold circuit connectable with said second source/drain and configured to sample and hold said reading voltage so that when the said writing voltage is blocked, said sample and hold circuit can supply said reading voltage to a control chip.