1. An oscillator circuit, comprising:
an oscillator configured to generate a first clock having a first frequency; and
a frequency jitter circuit including a charge pump having first and second capacitors, the charge pump being configured for transferring charges between the first and the second capacitors, the charge pump also configured to charge and discharge the first and the second capacitors repeatedly for providing a time-varying voltage having a second frequency that is lower than the first frequency;
wherein the time-varying voltage is coupled to the oscillator to vary the first frequency within a frequency range.
2. The oscillator circuit of claim 1 wherein the charge pump comprises:
a first switch for coupling the first capacitor to a voltage source;
a second switch for coupling the first capacitor to the second capacitor; and
a non-overlapping clock generator having an input terminal coupled to the first clock and being configured to produce a first phase clock and a second phase clock, the first and second phase clocks being non-overlapping signals;
wherein the first phase clock is configured to turn on the first switch to transfer a first charge between the voltage source and the first capacitor, and the second phase clock is configured to turn on the second switch to transfer a second charge between the first capacitor and the second capacitor.
3. The oscillator circuit of claim 2 wherein the second charge is a function of the first frequency and a capacitance of the first capacitor.
4. The oscillator circuit of claim 1 wherein the frequency jitter circuit further comprises a first comparator configured to compare the time-varying voltage alternately with a low threshold voltage and with a high threshold voltage for obtaining a second clock having the second frequency.
5. The oscillator circuit of claim 4 wherein a direction of charge transfer between the first and second capacitors is related to an output of the first comparator.
6. The oscillator circuit of claim 4 wherein the low threshold voltage and the high threshold voltage determine the magnitude of the time-varying voltage.
7. The oscillator circuit of claim 6 wherein the magnitude of the time-varying voltage determines the frequency range of the first frequency.
8. The oscillator circuit of claim 1 wherein the frequency jitter circuit further comprises a clock synchronizer circuit configured to align the transition of the second clock with the first clock and produce a synchronized second clock having a low state and a high state, wherein the state of the synchronized second clock determines the direction of charge transfer between the first and second capacitors.
9. The oscillator circuit of claim 4 wherein the oscillator further comprises:
a source current;
a sink current;
a source switch;
a sink switch;
a third capacitor, wherein the source current charges the third capacitor through the source switch; wherein the sink current discharges the third capacitor through the sink switch; and
a second comparator configured to produce a switching signal for controlling the source and sink switches.
10. The oscillator circuit of claim 9 wherein the second comparator further comprises:
a first input terminal coupled to a first threshold voltage;
a second input terminal coupled to the time-varying voltage;
a third input terminal coupled to a voltage of the third capacitor; and
an output terminal configured to produce the switching signal;
wherein the switching signal determines whether the voltage of the third capacitor is compared with the first threshold voltage or with the time-varying voltage.
11. A switched mode power supply (SMPS) controller, comprising:
an input terminal for receiving a feedback signal from a load of a power supply;
an output terminal for outputting a control signal for controlling an output of the power supply;
an oscillator circuit having an oscillator and a frequency jitter circuit, the oscillator being configured to generate a first clock having a first frequency, the frequency jitter circuit including a charge pump having first and second capacitors, the charge pump being configured for transferring charges between the first and the second capacitors, the charge pump also configured to charge and discharge the first and the second capacitors repeatedly for obtaining a time-varying voltage having a second frequency, wherein the time-varying voltage is coupled to the oscillator to vary the first frequency within a frequency range; and
a control logic circuit configured to provide the control signal based on a time-varying signal from the oscillator circuit and the feedback signal.
12. The controller of claim 11 wherein the charge pump in the oscillator circuit further comprises:
a first switch for coupling the first capacitor to a voltage source;
a second switch for coupling the first capacitor to the second capacitor; and
a non-overlapping clock generator having an input terminal coupled to the first clock and being configured to produce a first phase clock and a second phase clock, the first phase and second phase clocks being non-overlapping signals;
wherein the first phase clock is configured to turn on the first switch to transfer a first charge between the voltage source and the switched capacitor, and the second phase clock is configured to turn on the second switch to transfer a second charge between the first capacitor and the second capacitor.
13. The controller of claim 12, wherein the frequency jitter circuit further comprises a comparator configured to compare the time-varying voltage alternately with a low threshold voltage and with a high threshold voltage for obtaining a second clock having the second frequency.
14. The controller of claim 13 wherein a direction of charge transfer between the first and second capacitors is related to an output of the comparator.
15. The controller of claim 14 wherein the voltage source comprises:
a high reference voltage coupled to the first switch via a first voltage source switch; and
a low reference voltage coupled to the first switch via a second voltage source switch;
wherein the first and second voltage source switches are turned on and off with a synchronized low frequency clock.
16. The controller of claim 11 wherein the oscillator further comprises:
a source current;
a sink current;
a source switch;
a sink switch;
a third capacitor, wherein the source current charges the third capacitor through the source switch; wherein the sink current discharges the third capacitor through the sink switch; and
a second comparator configured to produce a switching signal for controlling the source and sink switches.
17. The controller of claim 16 wherein the second comparator further comprises:
a first input terminal coupled to a first threshold voltage;
a second input terminal coupled to the time-varying voltage;
a third input terminal coupled to a voltage of the third capacitor; and
an output terminal configured to produce the switching signal;
wherein the switching signal determines whether the voltage of the third capacitor is compared with the first threshold voltage or with the time-varying voltage.
18. The controller of claim 11 wherein the SMPS controller is a pulse width modulated (PWM) controller.
19. A power supply having a transformer with a primary winding coupled to a rectified dc voltage and a secondary winding for providing a regulated output, and a switched mode power supply (SMPS) controller, the SMPS controller comprising:
an input terminal for receiving a feedback signal from a load of a power supply;
an output terminal for outputting a control signal for controlling an output of the power supply;
an oscillator circuit having an oscillator and a frequency jitter circuit, the oscillator being configured to generate a first clock having a first frequency, the frequency jitter circuit including a charge pump having first and second capacitors, the charge pump being configured for transferring charges between the first and the second capacitors, the charge pump also configured to charge and discharge the first and the second capacitors repeatedly for obtaining a time-varying voltage having a second frequency, wherein the time-varying voltage is coupled to the oscillator to vary the first frequency within a frequency range; and
a control logic circuit configured to provide the control signal based on a time-varying signal from the oscillator circuit and the feedback signal.
20. The power supply of claim 19 wherein the charge pump further comprises:
a first switch for coupling the first capacitor to a voltage source;
a second switch for coupling the first capacitor to the second capacitor; and
a non-overlapping clock generator having an input terminal coupled to the first clock and being configured to produce a first phase clock and a second phase clock, the first and second phase clocks being non-overlapping signals;
wherein the first phase clock is configured to turn on the first switch to transfer a first charge between the voltage source and the first capacitor, and the second phase clock is configured to turn on the second switch to transfer a second charge between the first capacitor and the second capacitor.
21. The power supply of claim 19 wherein the oscillator further comprises a comparator having:
a first input terminal coupled to a first threshold voltage;
a second input terminal coupled to the time-varying voltage;
a third input terminal coupled to a voltage of the third capacitor; and
an output terminal configured to produce the switching signal;
wherein the switching signal determines whether the voltage of the third capacitor is compared with the first threshold voltage or with the time-varying voltage.
22. The power supply of claim 19 wherein the SMPS controller is a pulse width modulated (PWM) controller.
23. A method of generating a clock signal, the method comprising:
providing an oscillator circuit including a first comparator configured to produce the clock signal having a first frequency varying within a frequency range;
providing a frequency jitter circuit including a charge pump having first and second capacitors, the charge pump being configured for transferring charges between the first and the second capacitors, the charge pump also configured to charge and discharge the first and the second capacitors for producing a time-varying voltage; and
applying the time-varying voltage to the first comparator to vary the first frequency within the frequency range.
24. The method of claim 23 wherein the charge pump further comprises:
a first switch for coupling the first capacitor to a voltage source;
a second switch for coupling the first capacitor to the second capacitor; and
a clock generator having an input terminal coupled to the first clock and configured to produce a first phase clock and a second phase clock, the first phase and second phase clocks being non-overlapping signals;
wherein the first phase clock is configured to turn on the first switch to transfer a first charge between the voltage source and the first capacitor, and the second phase clock is configured to turn on the second switch to transfer a second charge between the first and the second capacitors.
25. The method of claim 24 wherein the frequency jitter circuit further comprises a second comparator configured to compare the time-varying voltage alternately with a low threshold voltage and with a high threshold voltage for obtaining a second clock having a second frequency, wherein a direction of charge transfer between the first and second capacitors is related to an output of the second comparator.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A user-interface method of selecting and presenting a collection of content items in which the presentation is ordered at least in part based on analyzing descriptive terms associated with content items of the collection and promoting the presentation order of content items associated with descriptive terms that are also associated with content items that have an increased level of recent selection occurrence by a plurality of users, the method comprising:
providing a set of content items, each content item having at least one associated descriptive term to describe the content item;
receiving a plurality of incremental input strings entered by a corresponding plurality of users for incrementally identifying desired content items;
in response to each of the plurality of incremental input strings entered by the plurality of users, presenting a subset of content items to each user of the plurality of users responsive to the incremental input string entered by the corresponding a user;
receiving actions from each of the users of the plurality of users selecting content items from the subset of content items presented to said user;
analyzing the descriptive terms associated with the content items selected by the plurality of users to detect an increase in the frequency with which descriptive terms are associated with the content items selected by the plurality of users;
in response to receiving subsequent incremental input entered by a user of the plurality of users, selecting and ordering a collection of content items based on promoting the order of content items associated with descriptive terms that have a recent increase in the frequency with which said descriptive terms are associated with the content items selected by the plurality of users; and
presenting the ordered collection of content items on a display device.
2. The method of claim 1, wherein each of at least a plurality of the content items is associated with a corresponding popularity value indicating a relative measure of a likelihood that the corresponding content item is desired by the user, and wherein ordering the collection of content items is further based on promoting the order of content items having popularity values that are higher relative to popularity values associated with other content items.
3. The method of claim 1, wherein the set of content items includes at least one of television program items, movie items, audiovideo media items, music items, contact information items, personal schedule items, web content items, and purchasable product items.
4. The method of claim 1, wherein the set of content items includes at least one of television program items, movie items, and audiovideo media items and the at least one associated descriptive term includes at least one of title, cast, director, content description, and keywords associated with the content.
5. The method of claim 1, wherein the set of content items is contained on at least one of a cable television system, a video-on-demand system, an IPTV system, and a personal video recorder.
6. The method of claim 1, wherein at least one of the incremental input and the subsequent incremental input are entered by the user on a hand-held device.
7. The method of claim 6, wherein the hand-held device has a plurality of overloaded keys, each of the overloaded keys representing two or more characters.
8. The method of claim 1, wherein at least one of the incremental input and the subsequent incremental input are entered by the user on at least one of a telephone, a PDA, a computer, and a remote control.
9. The method of claim 1, further comprising presenting the ordered collection of content items on at least part of a television screen.
10. The method of claim 1, wherein the display device is a hand-held device.
11. The method of claim 10, wherein the hand-held device is at least one of a telephone, a PDA, and a remote control.
12. The method of claim 1, wherein at least one of the incremental input and the subsequent incremental input comprises at least one prefix of a word for describing the desired content items.
13. The method of claim 12, wherein at least one of the incremental input and the subsequent incremental input comprises at least two prefixes of a phrase for describing the desired content items.
14. The method of claim 1, wherein at least one of receiving incremental input, presenting the subset of content items, receiving actions from the user, analyzing the descriptive terms, and selecting and ordering the collection of content items is performed on a server system remote from the user.
15. The method of claim 1, wherein at least one of receiving incremental input, presenting the subset of content items, receiving actions from the user, analyzing the descriptive terms, and selecting and ordering the collection of content items is performed on a user client device.