Several approximations can be used to fulfil the needs of the pulse
conversion. In the past, the monostable operation of a blocking
oscillator was used due to:
Sharp rise time.
Pulse shape parameters are straightforward dependant on circuit
Needs a few components.
What is a blocking oscillator?
A blocking oscillator consist of a BJT which is positively feed-backed
by a transformer and experiences a regenerative operation. Several
feed-back configurations have been considered and a study of the
choosing topology can be found in our repository.
Each of the pulse parameters are related as follows:
Pulse amplitude: tension of the desired pulse.
Rise and fall time: turns-ratio of the transformer, switching
capabilities of the BJT.
Pulse duration and tilt: mainly affected by the magnetizing
inductance of the transformer. Thanks to the inclusion of a resistor
in the feed-back loop, the circuit has lower the dependence from the
Overshoot, backswing, returnswing and ringing: if the turns-ratio of
the transformer is close to the optimal, these effects are
Recovery time: tension of the desired pulse and draining tension of
the diode-only based net.