02001101
Rev1 Page
6
of
16
phase shift mode. With the appropriate output inductor and the appropriate
capacitance across each switching device - in this case MOSFETS - there are
virtually no switching losses in the inverter. The only losses in the devices are I
2
R
losses associated with the Drain/Source resistance of the MOSFETS. Therefore,
the ZVS inverter also contributes to reduced losses, reduce EMI noise and a
reduction in overall system heatsink requirements.
Output Circuit
The output filter is a two stage RC filter designed to keep ripple and output noise
very low. For lower power units, such as the LDD-3000-250, a single stage filter
is used.
Control Circuit
The control circuit handles all the responsibilities associated with safe operation of
the laser diode. Controlled rise and fall times, as well as tight current regulation,
overvoltage and over power protection are controlled and monitored in the
control circuit.
Auxiliary Power
All internal power supply requirements as well as the ex/-15V and +5V
power supplies are derived from the power factor control boost inductor. All
auxiliary power supplies are regulated by standard linear regulators.
Figure 1
LDD-3000 Block Diagram
