Short duration variable amplitude high voltage pulse generator

• US 20070018504A1
• Filed: 10/14/2004
• Published: 01/25/2007
• Est. Priority Date: 10/14/2003
• Status: Abandoned Application

• Current Assignee: Daniel Lenz, Scott Wiener
• Original Assignee: Daniel Lenz, Scott Wiener
• Inventors: Lenz, Daniel, Wiener, Scott
• Application Number:
  US10/575,812
• Publication Number:
  US 20070018504A1
• Time in Patent Office: Days
• US Class Current: 307/108
• CPC Class Codes: G06F 1/025 for functions having two-valued amplitude, e.g. Walsh functions
• CPC Class Codes: H01J 2237/2485 Electric or electronic means
• CPC Class Codes: H01J 2237/2626 Pulsed source
• CPC Class Codes: H01J 2237/2852 Auto-emission (i.e. field-emission)
• CPC Class Codes: H01J 37/285 Emission microscopes, e.g. field-emission microscopes
• CPC Class Codes: H03K 3/57 the switching device being a semiconductor device

Abstract

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.

Claims

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.