Driver circuit for laser diode
A driver circuit for controlling a laser diode is described in response to a digital input signal, the driver circuit including: a switching means for receiving a digital input signal, the digital signal having a high voltage level and a low voltage level, the switching means generating a switching means output comprising a first switching voltage level in response to the high level and a second switching voltage level responsive to the low level; an emitter follower means having as its input the switching means output and generating an emitter follower output comprising a first follower output voltage level in response to the first switching voltage level and a second follower output voltage level in response to the second switching voltage level; a VMOS field effect transistor having a gate connected to the emitter follower means whereby the voltage level at the gate is substantially equal to the voltage level of the emitter follower output, and having a source biased to a pre-selected source voltage, the field effect trasnsistor enabled whenever the voltage level at the gate is substantially greater than the source voltage, and disabled when the voltage level at the gate is not substantially greater than the source voltage, one of the first and second follower output voltage levels being substantially greater than the source voltage and the other of the follower output voltage levels being no greater than a voltage level near the source voltage; and a laser diode connected in series with the field effect transistor and emitting light whenever the field effect transistor is enabled.
- Assignee:
- Optical Storage International U.S., Minneapolis, MN
- Patent Number(s):
- US 4594717
- OSTI ID:
- 5657324
- Resource Relation:
- Patent File Date: Filed date 27 Mar 1984
- Country of Publication:
- United States
- Language:
- English
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