Regulator system for charge pump circuits

• US 6,188,590 B1
• Filed: 06/17/1997
• Issued: 02/13/2001
• Est. Priority Date: 12/18/1996
• Status: Expired due to Term

• Current Assignee: Macronix International Co., Ltd.
• Original Assignee: Macronix International Co., Ltd.
• Inventors: Chang, Kuen-Long, Chuang, Weitong, Hung, Chun-Hsiung
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US08/860,151
• Time in Patent Office: 1,337 Days
• Field of Search: 363/59, 363/60, 323/314, 323/315, 327/536, 327/537, 331/14, 331/17
• US Class Current: 363/60
• CPC Class Codes: H02M 3/073 Charge pumps of the Schenkel-type
• CPC Class Codes: H02M 3/076 the clock signals being boosted to a value being higher than the input voltage value

Abstract

The present invention discloses a regulator system (112) for regulating the output current and voltage (Vout) of a charge pump circuit (104). It is observed that the output current and voltage (Vout) of a charge pump circuit (104) can be regulated by varying the amplitude and frequency of a set of clock signals (modulated clocks). The present invention comprises means (decoders 1, 2; AM, FM units) for generating a set of control signals (VAD1-VFDn) as the function of the output current and voltage (Vout). The set of control signals (VAD1-VFDn) is coupled to a clock signal generation circuit (130) that generates a set of clock signals (modulated clocks) having a magnitude and a frequency depending on this set of at least one control signal. This set of clock signals (modulated clocks) is then used to drive the charge pump circuit (104). It is found that this regulator circuit (112) consumes less power than prior art regulator circuits.

Claims

1. A regulator system for regulating output current of a charge pump circuit, said output current having a magnitude being controlled by a set of clock signals coupled to said charge pump circuit, said regulator system comprising:

a control circuit which generates a set of at least one control signal as a function of said output current; and

a clock circuit which generates said set of clock signals having a magnitude and a frequency, said magnitude depending on said set of at least one control signal;

said set of clock signals being applied to said charge pump circuit thereby varying said magnitude of said output current.

19. The regulator system of claim 1 wherein said charge pump circuit is a multi-stage charge pump circuit and said clock circuit comprises means for generating a set of multi-phase clock signals.

2. A regulator system for regulating output current of a charge pump circuit, said output current having a magnitude being controlled by a set of clock signals coupled to said charge pump circuit, said regulator system comprising:

a control circuit which generates a set of at least one control signal as a function of said output current; and

a clock circuit which generates said set of clock signals having a magnitude and a frequency, at least one of said magnitude and said frequency depending on said set of at least one control signal;

said set of clock signals being applied to said charge pump circuit thereby varying said magnitude of said output current;

wherein said set of at least one control signal contains a first and a second control signal, said control circuit comprising;

a sense circuit which generates a first set of voltage signals as a function of said output current;

a first circuit for generating said first control signal having a magnitude depending on said first set of voltages; and

a second circuit for generating said second control signal having a frequency depending on said first set of voltages.

3. The regulator system of claim 2 wherein said sense circuit comprises:

a plurality of current mirrors for generating a set of currents as a function of said output current; and

a plurality of resistive elements each connected to a corresponding one of said plurality of current mirrors for generating said set of first voltage signals when said set of currents flow through said set of resistive elements.

4. The regulator system of claim 3 wherein at least one of said resistive elements comprises a transistor.

5. The regulator system of claim 3 wherein said resistive elements have unequal resistance while said set of currents are equal, thereby generating said first set of voltage signals having unequal voltage levels.

6. The regulator system of claim 2 further comprising means for maintaining an output voltage of said charge pump circuit at a predetermined value.

7. The regulator system of claim 3 wherein said plurality of current mirrors comprise a plurality of transistors coupled to said output current.

8. The regulator system of claim 2 wherein said first circuit further comprises:

a first decoder for generating a second set of voltage signals as a function of said first set of voltage signals, said second set of voltage signals being non-sequential; and

an amplitude modulation unit for generating said first control signal as a function of said second set of voltage signals.

9. The regulator system of claim 2 wherein said second circuit further comprises:

a second decoder for generating a third set of voltage signals as a function of said first set of voltage signals, said third set of voltage signals being non-sequential; and

a frequency modulation unit for generating said second control signal as a function of said third set of voltage signals.

10. The regulator system of claim 8 wherein said first decoder comprises at least one logic circuit element.

11. The regulator system of claim 10 wherein said first decoder comprises at least one gate performing an OR function and at least one gate performing an AND function on said at least two members of said first set of voltage signals.

12. The regulator system of claim 9 wherein said second decoder comprises at least one logic circuit element.

13. The regulator system of claim 12 wherein said second decoder comprises at least one gate performing an AND function on said at least two members of said first set of voltage signals.

14. The regulator system of claim 8 wherein said amplitude modulation unit comprises a plurality of transistors, said transistors being turned on based on levels of said second set of voltage signals.

15. The regulator system of claim 14 wherein said transistor have their gate terminals connected to said second set of voltage signals and one of their source and drain terminals connected to a supply voltage.

16. The regulator system of claim 9 wherein said frequency modulation unit comprising:

a ring oscillator for generating a modulated clock signal having a oscillation frequency depending on capacitance at selected nodes;

at least one capacitor; and

means responsive to said third set of voltage signals for coupling said capacitor to one of said selected nodes of ring oscillator thereby modulating said oscillation frequency.

17. The regulator system of claim 16 wherein said capacitor comprises a field effect transistor.

18. The regulator system of claim 16 wherein said means for coupling comprises a transistor.

20. The regulator system of claim 16 further comprising at least one buffer coupled to at least one of said set of clock signals, said one buffer being controlled by said first control signal.

21. The regulator system of claim 20 wherein first control signal is used as a supply voltage of said one buffer.

22. A method for regulating output current of a charge pump circuit, said output current having a magnitude controlled by a set of clock signals coupled to said charge pump circuit, said method comprising the steps of:

generating a set of at least one control signal as a function of said output current;

generating said set of clock signals having a magnitude and a frequency, said magnitude depending on said set of at least one control signal; and

applying said set of clock signals to said charge pump circuit thereby varying said magnitude of said output current.

23. A method for regulating output current of a charge pump circuit, said output current having a magnitude controlled by a set of clock signals coupled to said charge pump circuit, said method comprising the steps of:

generating a set of at least one control signal as a function of said output current;

generating said set of clock signals having a magnitude and a frequency, at least one of said magnitude and said frequency depending on said set of at least one control signal; and

applying said set of clock signals to said charge pump circuit thereby varying said magnitude of said output current;

wherein said set of at least one control signal contains two control signals, and wherein said step of generating said set of at least one control signal comprises;

generating a first set of voltage signals as a function of said output current;

generating a first control signal having a magnitude depending on said first set of voltages; and

generating a second control signal having a frequency depending on said first set of voltages.

24. The method of claim 23 wherein said step of generating said first control signal comprises the steps of:

providing a first decoder for generating a second set of voltage signals as a function of said first set of voltage signals, said second set of voltage signals being non-sequential; and

generating said first control signal having a magnitude as a function of said second set of voltage signals.

25. The method of claim 24 wherein said step of generating said second control signal comprises the steps of:

providing a second decoder for generating a third set of voltage signals as a function of said first set of voltage signals, said third set of voltage signals being non-sequential; and

generating said second control signal having a frequency as a finction of said third set of voltage signals.

26. A regulator system for regulating output current of a charge pump circuit, said output current having a magnitude being controlled by a set of clock signals coupled to said charge pump circuit, said regulator system comprising:

a plurality of current mirrors for generating a set of currents as a function of said output current;

a plurality of resistive elements each connected to a corresponding one of said plurality of current mirrors for generating a set of first voltage signals when said set of currents flow through said set of resistive elements;

a first decoder for generating a second set of voltage signals as a function of said first set of voltage signals, said second set of voltage signals being non-sequential;

an amplitude modulation unit for generating a first control signal as a function of said second set of voltage signals;

a second decoder for generating a third set of voltage signals as a function of said first set of voltage signals, said third set of voltage signals being non-sequential;

a frequency modulation unit for generating a second control signal as a function of said third set of voltage signals; and

an oscillator generating said set of clock signals in response to said first and said second control signals;

said set of clock signals being applied to said charge pump circuit thereby varying said magnitude of said output current.

27. A regulator system for regulating output current of a charge pump circuit, said output current having a magnitude being controlled by a set of clock signals coupled to said charge pump circuit, said regulator system comprising:

a control circuit which generates a set of at least one control signal as a function of said output current; and

a clock circuit which generates said set of clock signals having a magnitude and a frequency, said magnitude and said frequency depending on said set of at least one control signal;

said set of clock signals being applied to said charge pump circuit thereby varying said magnitude of said output current.

28. A method for regulating output current of a charge pump circuit, said output current having a magnitude controlled by a set of clock signals coupled to said charge pump circuit, said method comprising the steps of:

generating a set of at least one control signal as a function of said output current;

generating said set of clock signals having a magnitude and a frequency, said magnitude and said frequency depending on said set of at least one control signal; and

applying said set of clock signals to said charge pump circuit thereby varying said magnitude of said output current.