High efficiency compact low power voltage doubler circuit

• US 5,493,486 A
• Filed: 03/17/1995
• Issued: 02/20/1996
• Est. Priority Date: 03/17/1995
• Status: Expired due to Fees

• Current Assignee: CTS Corporation
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Connell, Lawrence E., Keller, Anthony F.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): BERHANE, ADOLF D
• Application Number:
  US08/406,281
• Time in Patent Office: 340 Days
• Field of Search: 363/59, 363/60, 307/110, 320/1, 327/535, 327/536
• US Class Current: 363/60
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

What is described is a high efficiency voltage doubler (100). The high efficiency voltage doubler (100), has a charge-pump capacitor (30), an inverter (18), a coupling capacitor (24), a complementary switch pair (16), a DC biasing circuit (102), a charging circuit (106), and an input circuit (108). This structure is adapted for use in an integrated circuit, and provides the advantage of maximizing voltage doubled power output and minimizing current consumption with a minimal number of components.

Claims

1. A voltage doubler circuit, comprising;

an inverter circuit including an input and an output;

a complementary switch pair circuit including a N-channel transistor having a gate, drain and source and a P-channel transistor having a gate, drain and source, the gates of the N-channel transistor and the P-channel transistor being connected defining a common gate connection, the sources of the N-channel transistor and the P-channel transistor being connected defining a common source connection, whereby the P-channel transistor, the N-channel transistor and the inverter can be substantially simultaneously switched and the current drain is substantially minimized;

the input of the inverter circuit being coupled to the common gate connection via a coupling capacitor;

the output of the inverter circuit being coupled to the common source connection via a charge-pump capacitor; and

a DC biasing circuit being connected to the common gate connection, the DC biasing circuit for supplying a signal to the common gate connection, whereby the DC biasing circuit initially charges the coupling capacitor to a DC bias level and thereafter, under steady state conditions, compensates leakage currents present at the common gate connection.

2. The voltage doubler circuit of claim 1, wherein the common gate connection and the coupling capacitor are connected with a DC biasing circuit.

3. The voltage doubler circuit of claim 2, wherein the DC biasing circuit is a diode-connected device.

4. The voltage doubler circuit of claim 2, wherein the DC biasing circuit comprises a P-channel supply transistor having a gate, drain and source, the gate of the P-channel supply transistor is connected to the common gate connection and the drain of the P-channel supply transistor is connected to the common gate connection.

5. The voltage doubler circuit of claim 1, wherein the inverter circuit comprises a P-channel inverting transistor having a gate, drain and source and a N-channel inverting transistor having a gate, drain and source, the gates of the P-channel inverting transistor and the N-channel inverting transistor are connected to the input of the inverter circuit, and the drains of the P-channel inverting transistor and the N-channel inverting transistor are connected to the output of the inverter circuit.

6. The voltage doubler circuit of claim 2, wherein the DC biasing circuit comprises a N-channel supply transistor having a gate, drain and source, the source of the N-channel supply transistor being connected to the common gate connection, and the gate of the N-channel supply transistor being connected to the common source connection.

7. The voltage doubler circuit of claim 1, wherein the drain of the P-channel transistor defines a voltage doubler output node, and the input of the inverter circuit defines a voltage doubler input node.

8. The voltage doubler circuit of claim 7, wherein the inverter circuit includes a P-channel inverting transistor having a source, and a supply voltage is applied to the drain of the N-channel transistor and the source of the P-channel inverting transistor, and the voltage doubler output node comprises about twice as large a voltage as the supply voltage.

9. A voltage doubler circuit, comprising:

a first inverter circuit including an input and an output;

a complementary switch pair circuit including a N-channel transistor having a gate, drain and source and a P-channel transistor having a body, gate, drain and source, the gates of the N-channel transistor and the P-channel transistor being connected defining a common gate connection, the sources of the N-channel transistor and the P-channel transistor being connected defining a common source connection, whereby the P-channel transistor, the N-channel transistor and the first inverter circuit can be substantially simultaneously switched and the current drain is substantially minimized;

the input of the first inverter circuit being coupled to the common gate connection via a coupling capacitor;

the output of the first inverter circuit being coupled to the common source connection via a charge-pump capacitor; and

a biasing circuit being connected to the body of the complementary switch pair P-channel transistor, the biasing circuit driving the body of the complementary switch pair P-channel transistor to a predetermined potential substantially the same as that of the drain of the complementary switch pair P-channel transistor, whereby a potential between any of the gate, drain, source and body of the complementary switch pair P-channel transistor substantially never exceeds a voltage greater than a positive supply voltage which allows for a lower voltage, higher current transistor design.

10. A voltage doubler circuit, comprising:

a first inverter circuit including an input and an output;

a complementary switch pair circuit including a N-channel transistor having a gate, drain and source and a P-channel transistor having a body, gate, drain and source, the gates of the N-channel transistor and the P-channel transistor being connected defining a common gate connection, the sources of the N-channel transistor and the P-channel transistor being connected defining a common source connection, whereby the P-channel transistor, the N-channel transistor and the first inverter circuit can be substantially simultaneously switched and the current drain is substantially minimized;

the input of the first inverter circuit being coupled to the common gate connection via a coupling capacitor;

the output of the first inverter circuit being coupled to the common source connection via a charge-pump capacitor; and

a biasing circuit including a biasing capacitor and a P-channel biasing transistor having a body, gate, drain and source, the source of the P-channel biasing transistor being connected to the common source connection, the gate of the P-channel biasing transistor being connected to the common gate connection, the biasing capacitor and the drain and body of the P-channel biasing transistor being connected to the body of the complementary switch pair P-channel transistor; and

the biasing circuit driving the body of the complementary switch pair P-channel transistor to a predetermined potential substantially the same as that of the drain of the complementary switch pair P-channel transistor, whereby a potential between any of the gate, drain, source and body of the complementary switch pair P-channel transistor substantially never exceeds a voltage greater than a positive supply voltage which allows for a lower voltage, higher current transistor design.

11. The voltage doubler circuit of claim 10, further comprising a DC biasing circuit being connected to the common gate connection, whereby the DC biasing circuit initially charges the coupling capacitor to a DC bias level and thereafter, under steady state conditions, compensates leakage currents present at the common gate connection.

12. The voltage doubler circuit of claim 11, wherein the DC biasing circuit is a N-channel supply transistor having a gate, drain and source, the source of the N-channel supply transistor being connected to the common gate connection and the gate of the N-channel supply transistor being connected to the common source connection.

13. The voltage doubler circuit of claim 11, wherein the DC biasing circuit is a diode-connected device.

14. The voltage doubler circuit of claim 11, wherein the DC biasing circuit comprises a P-channel supply transistor having a gate, drain and source, the gate of the P-channel supply transistor is connected to the common gate connection and the drain of the P-channel supply transistor is connected to the common gate connection.

15. The voltage doubler circuit of claim 11, wherein the DC biasing circuit includes a N-channel supply transistor having a gate, drain and source, a secondary N-channel supply transistor having a gate, drain and source, a second inverter circuit with an input and an output, and a charge-pump biasing capacitor, the gate of the secondary N-channel supply transistor and the source of the N-channel supply transistor being connected to the complementary switch pair common gate connection, the source of the secondary N-channel supply transistor being connected to the gate of the N-channel supply transistor, the gate of the N-channel supply transistor being coupled to the output of the second inverter circuit via the charge-pump biasing capacitor, and the input of the second inverter circuit being connected to the input of the first inverter circuit.

16. The voltage doubler circuit of claim 10, further comprising a charging circuit including a resistor, a P-channel charging transistor having a gate, drain and a source, and a third inverter circuit with an input, an output and a voltage source tap, the resistor being connected to the source of the P-channel charging transistor, the drain of the P-channel charging transistor being connected to the drain of the complementary switch pair P-channel transistor, the gate of the P-channel charging transistor being connected to the output of the third inverter circuit, the input of the third inverter circuit being connected to a disable input signal, and the voltage source tap of the third inverter circuit being connected to the drain of the complementary switch pair P-channel transistor.

17. The voltage doubler circuit of claim 10, further comprising an input circuit including a NOR gate with a first and second input and an output and an inverter gate with an input and output, the first input of the NOR gate being connected to an input signal, the second input of the NOR gate being connected to a disable input signal, the output of the NOR gate being connected to the input of the inverter gate, and the output of the inverter gate being connected to the input of the first inverter circuit.

18. The voltage doubler circuit of claim 10, further comprising a DC biasing circuit, a charging circuit, and an input circuit.

19. The voltage doubler circuit of claim 18, wherein the voltage doubler circuit comprises an integrated circuit.

20. The voltage doubler circuit of claim 10, wherein the drain of the P-channel transistor defines a voltage doubler output node, and the input of the first inverter circuit defines a voltage doubler input node.

21. The voltage doubler circuit of claim 10, wherein the first inverter circuit includes a P-channel inverting transistor having a source, and a supply voltage is applied to the drain of the N-channel transistor and the source of the P-channel inverting transistor, and the voltage doubler output node comprises about twice as large a voltage as the supply voltage.