Fast voltage level shifter circuit

• US 9,564,882 B2
• Filed: 11/27/2015
• Issued: 02/07/2017
• Est. Priority Date: 01/27/2010
• Status: Active Grant

• Current Assignee: Solaredge Technologies Incorporated
• Original Assignee: Solaredge Technologies Incorporated
• Inventors: Gazit, Meir
• Primary Examiner(s): JAGER, RYAN C
• Application Number:
  US14/953,053
• Publication Number:
  US 20160087613A1
• Time in Patent Office: 438 Days
• Field of Search: 327/333, 326/80, 326/81
• US Class Current: 1/1
• CPC Class Codes: H03K 19/0185 using field effect transistors only
• CPC Class Codes: H03K 19/018507 Interface arrangements
• CPC Class Codes: H03K 19/018521 of complementary type, e.g. CMOS
• CPC Class Codes: H03K 3/356 Bistable circuits
• CPC Class Codes: H03K 3/356104 using complementary field-effect transistors H03K3/35625 takes precedence

Abstract

A voltage level shifting circuit with an input terminal and an output terminal. The level shifting circuit has a field-effect transistor (FET) switch with a gate attached to the input terminal, a drain attached to the output terminal and a source attached to a current changing mechanism. The current changing mechanism includes a current mirror circuit having an output connected between the source and an electrical earth. The output of the current mirror circuit is preferably adapted to change a current flowing between the drain and the source based on an input voltage applied to the gate.

Claims

1. A circuit comprising:

a switch configured to produce an output voltage on an output terminal in response to an input voltage applied to an input terminal and in response to a current drawn through the switch;

a current mirror circuit having a control input and configured to draw the current through the switch in response to the control input; and

a charge storage circuit connected to the input terminal and to the control input of the current mirror circuit, wherein the charge storage circuit is configured to discharge a stored charge into the control input in response to the input voltage.

2. The circuit of claim 1, wherein the charge storage circuit comprises a capacitor connected between the input terminal and the control input of the current mirror circuit.

3. The circuit of claim 1, wherein the charge storage circuit comprises:

a first diode;

a capacitor connected to a first anode of the first diode, wherein a first cathode of the first diode is connected to the control input of the current mirror circuit; and

a second diode, wherein a second cathode of the second diode is connected to the first anode.

4. The circuit of claim 1, further comprising an inverting amplifier, wherein the charge storage circuit is connected to the input terminal through the inverting amplifier.

5. The circuit of claim 1, further comprising:

a resistor connected between the output terminal and the switch; and

a capacitor in parallel with the resistor.

6. The circuit of claim 1, further comprising:

a resistor connected between the output terminal and the switch;

a capacitor in parallel with the resistor; and

a diode having a cathode connected between the switch and the resistor,

wherein the output voltage is based on a voltage between the output terminal and an anode of the diode.

7. The circuit of claim 1, wherein the charge storage circuit comprises a battery.

8. The circuit of claim 1, wherein the switch is selected from a group consisting of:

a silicon controlled rectifier (SCR), an insulated gate bipolar junction transistor (IGBT), a bipolar junction transistor (BJT), a field effect transistor (FET), a junction field effect transistor (JFET), a switching diode, an electrical relay, a reed relay, a solid state relay, an insulated gate field effect transistor (IGFET), a diode for alternating current (DIAC), and a triode for alternating current TRIAC.

9. A method comprising:

applying an input voltage to an input terminal of a circuit, wherein the circuit comprises;

a switch configured to cause an output voltage to be produced on an output terminal in response to the input voltage applied to the input terminal and in response to a current drawn through the switch;

a current mirror circuit having a control input and configured to draw the current through the switch in response to the control input; and

a charge storage circuit connected to the input terminal and to the control input of the current mirror circuit, wherein the charge storage circuit is configured to discharge a stored charge into the control input in response to the input voltage; and

varying the input voltage to cause the charge storage circuit to discharge the stored charge into the control input of the current mirror circuit and thereby produce the output voltage.

10. The method of claim 9, wherein the charge storage circuit comprises a capacitor connected between the input terminal and the control input of the current mirror circuit, and wherein the varying the input voltage comprises varying the input voltage to cause the capacitor to discharge the stored charge into the control input of the current mirror circuit and thereby produce the output voltage.

11. The method of claim 9, wherein the charge storage circuit comprises:

a first diode;

a capacitor connected to a first anode of the first diode, wherein a first cathode of the first diode is connected to the control input of the current mirror circuit; and

a second diode, wherein a second cathode of the second diode is connected to the first anode,

wherein the varying the input voltage comprises varying the input voltage to cause the capacitor to discharge the stored charge through the first diode into the control input of the current mirror circuit and thereby produce the output voltage.

12. The method of claim 9, wherein the charge storage circuit comprises a battery.

13. The method of claim 9, wherein the switch is selected from a group consisting of:

a silicon controlled rectifier (SCR), an insulated gate bipolar junction transistor (IGBT), a bipolar junction transistor (BJT), a field effect transistor (FET), a junction field effect transistor (JFET), a switching diode, an electrical relay, a reed relay, a solid state relay, an insulated gate field effect transistor (IGFET), a diode for alternating current (DIAC), and a triode for alternating current TRIAC.

14. A circuit comprising:

an input terminal;

an output terminal;

a level shifting circuit configured to produce an output voltage at the output terminal responsive to an input voltage at the input terminal;

a current mirror circuit having a control input and configured to draw current through the level shifting circuit in response to the control input to thereby produce the output voltage; and

a charge storage circuit connected to the input terminal and to the control input of the current mirror circuit, wherein the charge storage circuit is configured to discharge a stored charge into the control input in response to the input voltage.

15. The circuit of claim 14, wherein the charge storage circuit comprises a capacitor connected between the input terminal and the control input of the current mirror circuit.

16. The circuit of claim 14, wherein the charge storage circuit comprises:

a first diode;

a capacitor connected to a first anode of the first diode, wherein a first cathode of the first diode is connected to the control input of the current mirror circuit; and

a second diode, wherein a second cathode of the second diode is connected to the first anode.

17. The circuit of claim 14, further comprising an inverting amplifier, wherein the charge storage circuit is connected to the input terminal through the inverting amplifier.

18. The circuit of claim 14, wherein the level shifting circuit comprises:

a resistor connected between the output terminal and a switch that is responsive to the input voltage; and

a capacitor in parallel with the resistor.

19. The circuit of claim 14, further comprising:

a resistor connected between the output terminal and a switch that is responsive to the input voltage;

a capacitor in parallel with the resistor; and

a diode having a cathode connected between the switch and the resistor,

wherein the output voltage is based on a voltage between the output terminal and an anode of the diode.

20. The circuit of claim 14, wherein the charge storage circuit comprises a battery.