CIRCUIT FOR GENERATING A VOLTAGE WAVEFORM

• US 20140347104A1
• Filed: 05/02/2014
• Published: 11/27/2014
• Est. Priority Date: 05/23/2013
• Status: Active Grant

• Current Assignee: Shimadzu Corporation
• Original Assignee: Shimadzu Corporation
• Inventors: GILL, Matthew Clive, DING, Li, TAYLOR, Steven Douglas, NUTTALL, James Edward
• Granted Patent: US 9,391,593 B2
• Time in Patent Office: Days
• US Class Current: 327/124
• CPC Class Codes: H01J 49/022 Circuit arrangements, e.g. for generating deviation currents or voltages regulating electric or magnetic variables in general, e.g. current, magnetic field G05F; Components associated with high voltage supply high voltage supply per se H02M
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H03K 17/6871 the output circuit comprising more than one controlled field-effect transistor
• CPC Class Codes: H03K 17/6874 in a symmetrical configuration
• CPC Class Codes: H03K 3/012 Modifications of generator to improve response time or to decrease power consumption
• CPC Class Codes: H03K 3/356 Bistable circuits
• CPC Class Codes: H03K 5/00006 Changing the frequency modulating pulses H03K7/00; frequency dividers H03K21/00 - H03K29/00; additive or subtractive mixing of two pulse rates into one G06F7/605; pulse rate dividers G06F7/68
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A circuit for generating a voltage waveform at an output node. The circuit includes a voltage rail connected to the output node via a voltage rail switch; an anchor node connected to the output node via an inductor and a bidirectional switch, wherein the bidirectional switch includes two or more transistors connected in series; and a control unit configured to change the voltage at the output node by controlling the voltage rail switch and the bidirectional switch so that, if a load capacitance is connected to the output node, a resonant circuit is established between the inductor and the load capacitance. The circuit may be included in an apparatus for use in processing charged particles, e.g. for use in performing mass spectrometry or ion mobility spectrometry.

Claims

1. A circuit for generating a voltage waveform at an output node, the circuit including:

a voltage rail connected to the output node via a voltage rail switch;

an anchor node connected to the output node via an inductor and a bidirectional switch, wherein the bidirectional switch includes two or more transistors connected in series; and

a control unit configured to change the voltage at the output node by controlling the voltage rail switch and the bidirectional switch so that, if a load capacitance is connected to the output node, a resonant circuit is established between the inductor and the load capacitance.

2. A circuit according to claim 1, wherein the two or more transistors connected in series include a pair of MOSFET transistors connected back-to-back.

3. A circuit according to claim 1, wherein the circuit is a switching circuit for generating a switching waveform that switches between a first voltage and a second voltage.

4. A circuit according to claim 3, wherein the control unit is configured to change the frequency at which the switching voltage waveform switches between the first voltage and the second voltage.

5. A circuit according to claim 1, wherein the circuit includes:

a first voltage rail connected to the output node via a first voltage rail switch;

a second voltage rail connected to the output node via a second voltage rail switch;

wherein the control unit is configured to change the voltage at the output node by controlling the first voltage rail switch, the second voltage rail switch and the bidirectional switch so that, if a load capacitance is connected to the output node, a resonant circuit is established between the inductor and the load capacitance.

6. A circuit according to claim 5, wherein the control unit of the circuit is configured to control the circuit to operate according to a control method including:

opening the bidirectional switch and closing the first voltage rail switch so that the output node is clamped at the voltage of the first voltage rail;

causing the voltage at the output node to swing towards the voltage of the second voltage rail by opening the first voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

opening the bidirectional switch and closing the second voltage rail switch so that the output node is clamped at the voltage of the second voltage rail;

causing the voltage at the output node to swing towards the voltage of the first voltage rail by opening the second voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance.

7. A circuit according to claim 1, wherein the control unit of the circuit is configured to control the circuit to operate according to a control method including:

opening the bidirectional switch and closing the voltage rail switch so that the output node is clamped at the voltage of the voltage rail;

causing the voltage at the output node to swing towards a floating voltage by opening the voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

opening the bidirectional switch without closing the voltage rail switch so that the output node is held at the floating voltage;

causing the voltage at the output node to swing towards the voltage of the voltage rail by closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance.

8. A circuit according to claim 1, wherein the control unit of the circuit is configured to control the circuit to operate according to a control method including:

opening the bidirectional switch and closing the voltage rail switch so that the output node is clamped at the voltage of the voltage rail;

causing the voltage at the output node to swing away from and back towards the voltage of the voltage rail by opening the first voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance.

9. A circuit according to claim 1, wherein the circuit includes:

a voltage rail connected to an output node via a voltage rail switch and connected to an additional output node via an additional voltage rail switch;

a first anchor node connected to the output node via an inductor and a bidirectional switch that includes two or more transistors connected in series;

a second anchor node connected to the additional output node via an inductor and a bidirectional switch that includes two or more transistors connected in series;

wherein the control unit is configured to change the voltage at the output node by controlling the voltage rail switch and the bidirectional switch connected to the first anchor node so that, if a load capacitance is connected between the output node and the additional output node, a resonant circuit is established between the inductor connected to the first anchor node and the load capacitance; and

wherein the control unit is configured to change the voltage at the additional output node by controlling the additional voltage rail switch and the bidirectional switch connected to the second anchor node so that, if a load capacitance is connected between the output node and the additional output node, a resonant circuit is established between the inductor connected to the second anchor node and the load capacitance.

10. A circuit according to claim 9, wherein the circuit includes:

a first voltage rail connected to the output node via a first voltage rail switch and connected to the additional output node via an additional first voltage rail switch;

a second voltage rail connected to the output node via a second voltage rail switch and connected to the additional output node via an additional second voltage rail switch;

a first anchor node connected to the output node via an inductor and a bidirectional switch that includes two or more transistors connected in series;

a second anchor node connected to the additional output node via an inductor and a bidirectional switch that includes two or more transistors connected in series;

wherein the control unit is configured to change the voltage at the output node by controlling the first voltage rail switch, the second voltage rail switch and the bidirectional switch connected to the first anchor node so that, if a load capacitance is connected between the output node and the additional output node, a resonant circuit is established between the inductor connected to the first anchor node and the load capacitance; and

wherein the control unit is configured to change the voltage at the additional output node by controlling the additional first voltage rail switch, the additional second voltage rail switch and the bidirectional switch connected to the second anchor node so that, if a load capacitance is connected between the output node and the additional output node, a resonant circuit is established between the inductor connected to the second anchor node and the load capacitance.

11. A circuit according to claim 9, wherein:

the circuit includes a shared inductor, wherein the shared inductor acts as both the inductor connected to the first anchor node and the inductor connected to the second anchor node;

the circuit includes a shared bidirectional switch, wherein the shared bidirectional switch acts as both the bidirectional switch connected to the first anchor node and the bidirectional switch connected to the second anchor node;

the output node acts as the second anchor node; and

the additional output node acts as the first anchor node.

12. A circuit according to claim 9, wherein the circuit includes:

separate inductors that act as the inductor connected to the first anchor node and the inductor connected to the second anchor node;

separate bidirectional switches that act as the bidirectional switch connected to the first anchor node and the bidirectional switch connected to the second anchor node;

first and second anchor nodes that are separate from the output node and additional output node.

13. A circuit according to claim 1, wherein the circuit is included in an apparatus for use in processing charged particles, the apparatus further including a load capacitance to which the output node of the circuit is connected so that, in use, the load capacitance receives a voltage waveform generated by the circuit.

14. A circuit according to claim 13, wherein:

the circuit includes an output node and an additional output node;

the apparatus includes a load capacitance, wherein the load capacitance includes;

at least one first electrode to which the output node of the circuit is connected so that, in use, the at least one first electrode receives a voltage waveform generated by the circuit;

at least one second electrode to which the additional output node of the circuit is connected so that, in use, the at least one load capacitance receives an additional voltage waveform generated by the circuit.

15. A method of controlling a circuit that includes:

a voltage rail connected to the output node via a voltage rail switch;

an anchor node connected to the output node via an inductor and a bidirectional switch, wherein the bidirectional switch includes two or more transistors connected in series; and

a control unit configured to change the voltage at the output node by controlling the voltage rail switch and the bidirectional switch so that, if a load capacitance is connected to the output node, a resonant circuit is established between the inductor and the load capacitance;

wherein the method includes a controlling the circuit to operate according to any one of the following control methods;

a first control method that includes;

opening the bidirectional switch and closing a first voltage rail switch so that the output node is clamped at a voltage of a first voltage rail, wherein the first voltage rail is connected to the output node via the first voltage rail switch;

causing the voltage at the output node to swing towards a voltage of a second voltage rail by opening the first voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

opening the bidirectional switch and closing a second voltage rail switch so that the output node is clamped at a voltage of the second voltage rail, wherein the second voltage rail is connected to the output node via the second voltage rail switch;

causing the voltage at the output node to swing towards the voltage of the first voltage rail by opening the second voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

a second control method that includes;

opening the bidirectional switch and closing the voltage rail switch so that the output node is clamped at the voltage of the voltage rail;

causing the voltage at the output node to swing towards a floating voltage by opening the voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

opening the bidirectional switch without closing the voltage rail switch so that the output node is held at the floating voltage;

causing the voltage at the output node to swing towards the voltage of the voltage rail by closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

a third control method that includes;

opening the bidirectional switch and closing the voltage rail switch so that the output node is clamped at the voltage of the voltage rail;

causing the voltage at the output node to swing away from and back towards the voltage of the voltage rail by opening the first voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance.

16. A computer-readable medium having computer-executable instructions configured to control a circuit that includes:

a voltage rail connected to the output node via a voltage rail switch;

an anchor node connected to the output node via an inductor and a bidirectional switch, wherein the bidirectional switch includes two or more transistors connected in series; and

a control unit configured to change the voltage at the output node by controlling the voltage rail switch and the bidirectional switch so that, if a load capacitance is connected to the output node, a resonant circuit is established between the inductor and the load capacitance;

wherein the computer-executable instructions are configured to control the circuit to operate according to any one of the following control methods;

a first control method that includes;

opening the bidirectional switch and closing a first voltage rail switch so that the output node is clamped at a voltage of a first voltage rail, wherein the first voltage rail is connected to the output node via the first voltage rail switch;

causing the voltage at the output node to swing towards a voltage of a second voltage rail by opening the first voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

opening the bidirectional switch and closing a second voltage rail switch so that the output node is clamped at a voltage of the second voltage rail, wherein the second voltage rail is connected to the output node via the second voltage rail switch;

causing the voltage at the output node to swing towards the voltage of the first voltage rail by opening the second voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

a second control method that includes;

opening the bidirectional switch and closing the voltage rail switch so that the output node is clamped at the voltage of the voltage rail;

causing the voltage at the output node to swing towards a floating voltage by opening the voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

opening the bidirectional switch without closing the voltage rail switch so that the output node is held at the floating voltage;

causing the voltage at the output node to swing towards the voltage of the voltage rail by closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance;

a third control method that includes;

opening the bidirectional switch and closing the voltage rail switch so that the output node is clamped at the voltage of the voltage rail;

causing the voltage at the output node to swing away from and back towards the voltage of the voltage rail by opening the first voltage rail switch and closing the bidirectional switch so that a resonant circuit is established between the inductor and the load capacitance.