Obtaining elevated output voltages from charge pump circuits

• US 8,476,964 B1
• Filed: 05/17/2012
• Issued: 07/02/2013
• Est. Priority Date: 05/17/2012
• Status: Active Grant

• Current Assignee: Copeland Comfort Control LP (Emerson Electric Company)
• Original Assignee: Emerson Electric Company
• Inventors: Atri, Jagdish
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): Kim, Jung H.
• Application Number:
  US13/473,673
• Time in Patent Office: 411 Days
• Field of Search: 327/536, 327/530, 327/535, 327/537, 327/538
• US Class Current: 327/536
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

According to various aspects, exemplary embodiments are disclosed of a thermostat that includes a charge pump configured to provide a charge pump supply voltage relative to a signal ground of the charge pump. One or more diodes are connected between the charge pump and the signal ground. The one or more diodes are configured to provide a forward voltage drop to increase the charge pump supply voltage.

Claims

1. A thermostat comprising:

a charge pump configured to provide a charge pump supply voltage relative to a signal ground of the charge pump wherein the charge pump has a ground terminal; and

one or more diodes connected between the ground terminal of the charge pump and the signal ground and configured to provide a forward voltage drop to increase the charge pump supply voltage;

wherein the charge pump is operable for outputting a regulated output voltage absent all of the one or more diodes and for outputting a charge pump supply voltage beyond the regulated output voltage with the one or more diodes present.

2. The thermostat of claim 1, wherein the one or more diodes comprise a single diode.

3. The thermostat of claim 2, wherein the single diode is a Schottky diode.

4. The thermostat of claim 1, wherein:

the charge pump is operable for outputting a regulated 3.3-volt output voltage as the charge pump supply voltage; and

the thermostat further comprises a film-compensated super-twisted nematic (FSTN) display device powered by the increased supply voltage.

5. The thermostat of claim 1, wherein the charge pump comprises a charge pump integrated circuit (IC).

6. The thermostat of claim 1, wherein:

the charge pump comprises a charge pump integrated circuit (IC) that is operable for outputting a regulated 3.3-volt output voltage absent the one or more diodes and for outputting a charge pump supply voltage beyond 3.3 volts with the one or more diodes present;

the one or more diodes comprise a single Schottky diode; and

the thermostat further comprises a film-compensated super-twisted nematic (FSTN) display device powered by the increased supply voltage.

7. A power supply circuit comprising:

a charge pump integrated circuit (IC) configured to output a power supply voltage relative to a signal ground of the charge pump IC wherein the charge pump IC has a ground terminal; and

one or more diodes connected between the ground terminal of the charge pump IC and the signal ground and configured to provide a forward voltage drop to increase the power supply voltage;

wherein the charge pump IC is operable for outputting a regulated output voltage absent all of the one or more diodes and for outputting a charge pump supply voltage beyond the regulated voltage with the one or more diodes present.

8. The power supply circuit of claim 7, wherein the one or more diodes comprise a single diode.

9. The power supply circuit of claim 8, wherein the single diode is a Schottky diode.

10. The power supply circuit of claim 7, wherein the regulated output voltage is regulated at 3.3 volts.

11. A thermostat comprising the power supply circuit of claim 7.

12. The thermostat of claim 11, wherein:

the charge pump IC is operable for outputting a regulated 3.3-volt output voltage absent the one or more diodes and for outputting a charge pump supply voltage beyond 3.3 volts with the one or more diodes present;

the one or more diodes comprise a single diode; and

the thermostat further comprises a film-compensated super-twisted nematic (FSTN) display device powered by the increased power supply voltage.

13. A method of boosting voltage output of a power supply circuit, the method comprising:

adding one or more diodes between a ground terminal of a charge pump for providing a regulated voltage output of a power supply circuit and a signal ground of the charge pump, where the charge pump is operable to provide the regulated voltage output relative to the signal ground absent any diodes between the ground terminal of the charge pump and the signal ground and to provide a charge pump supply voltage beyond the regulated voltage output with the one or more diodes present.

14. The method of claim 13, wherein adding the one or more diodes comprises adding a single Schottky diode.

15. The method of claim 13, performed to provide power to a film-compensated super-twisted nematic (FSTN) display device of a thermostat.

16. The method of claim 13, wherein the charge pump includes a charge pump integrated circuit (IC).

17. The method of claim 16, wherein the charge pump IC is configured to provide a regulated 3.3-volt output as the voltage output.

18. The method of claim 13, wherein:

adding the one or more diodes comprises adding a single Schottky diode;

the charge pump includes a charge pump integrated circuit (IC) configured to provide a regulated 3.3-volt output as the voltage output; and

the method is performed to provide power to a film-compensated super-twisted nematic (FSTN) display device of a thermostat.