摘要 |
An LD driver is disclosed where the power dissipation is reduced without enlarging the circuit scale. The LD driver, which drives a tunable LD including a SG-DGB region, a CSG-DBR region, and an SOA region, includes a DC/DC converter connected to current sources or voltage sources each coupled with at least two regions of the SG-DFB, CSG-DBR and SOA regions, and a voltage controller to control the output of the DC/DC converter which is commonly provided to the current sources or the voltage sources. The voltage controller independently monitors the bias conditions of the at least two regions above, and sets the output of the DC/DC converter so as to exceed a largest voltage among voltages currently provided to respective regions by a preset margin to operate the current sources or the voltage sources normally.
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