ENHANCED LINEARITY DVD WRITING CURRENT CIRCUIT

摘要

A writing current circuit (42) supplies a controlled electrical current to a laser diode (34) for recording data swiftly onto a DVD (16) . A plurality of current sources (62) in the writing current circuit (42) supply electrical current directly to the laser diode (34) . Each current source (62) respectively receives a single output signal from a current control register (52) included in the writing current circuit (42) which activates or deactivates the current source (62) for supplying a particular quantity of current to the laser diode (34) . In one aspect, a pair of current reference signals received by the current source (62) control electrical current supply to the diode (34) . Incorporated into these controlling reference signals is a simulation of electrical characteristics of the diode (34) . In another aspect, each current source (62) responds to a logical inverse of the output signal from the current control register (52) for controlling overshoot in voltage applied across the diode (34) .