Short duration variable amplitude high voltage pulse generator
An improved electrical pulse generator incorporating MOSFET components, a programmable high voltage power supply, and a shaping network for generating short duration signals having narrow pulse widths and short rise times.
1 . A pulser circuit for generating an electrical pulse of short duration for use in an atom probe, comprising:
(a) a circuit comprising at least a first node;
(b) a voltage supply for charging the first node;
(b) a switching network having a first switch operable between a conductive state for shorting the first node to a grounded node and a nonconductive state for opening the circuit between the first node and the grounded node, and an RC network having a time constant of less than 33 microseconds, comprising at least one resistor connected between the first node and the voltage supply, and wherein the capacitance is a combination of the switch capacitance and at least one capacitor connected to the node, and
(d) wherein the switch is in a nonconductive state to charge the RC network and the switch is in a conductive state to discharge the RC network, thereby generating the electrical pulse.
2 . The pulser circuit of claim 1 further comprising a controllable shaping network for providing pulses of selectable amplitudes and shapes.
3 . The pulser circuit of claim 1 further comprising at least one switching network connected in series with the RC network
4 . The pulser circuit of claim 1 further comprising a shunting network for shunting transients to a low impedance node.
5 . A pulser circuit for generating an electrical pulse of short duration for use in an atom probe, comprising:
(a) a circuit comprising at least a first node;
(b) a voltage supply for charging the first node;
(c) a switch operable between a conductive state for shorting the first node to a grounded node and a nonconductive state for opening the circuit between the first node and the grounded node;
(d) a controllable RC network, comprising at least one resistor connected between the first node and the voltage supply, and wherein the capacitance is a combination of the switch capacitance and at least one capacitor connected to the node, for generating pulses having selectable amplitudes and shapes; and
(e) wherein the switch is in a nonconductive state to charge the RC network and the switch is in a conductive state to discharge the RC network, thereby generating the electrical pulse.
6 . A pulser circuit for generating an electrical pulse of short duration for use in an atom probe, comprising:
(a) a circuit comprising at least a first node;
(b) a voltage supply for charging the first node;
(c) a first switch operable between a conductive state for shorting the first node to a grounded node and a nonconductive state for opening the circuit between the first node and the grounded node;
(d) an RC network, comprising at least one resistor connected between the first node and the voltage supply, and wherein the capacitance is a combination of the switch capacitance and at least one capacitor connected to the node,
(e) at least one or more second switching networks connected in series;
(f) wherein the switch is in a nonconductive state to charge the RC network and the switch is in a conductive state to discharge the RC network, thereby generating the electrical pulse.