Three-pin buck and four-pin boost converter having open loop output voltage control
First Claim
1. A switching mode power converter including an integrated circuit controller, wherein none of the pins of the integrated circuit controller are coupled to monitor a regulated output of the power converter, the integrated circuit controller comprising:
- a. a first pin coupled to a first terminal of a first switch;
b. a second pin coupled to a second terminal of the first switch and to a first terminal of a second switch;
c. a third pin coupled to a second terminal of the second switch; and
d. a circuit coupled to control the first switch and the second switch by comparing a signal proportional to a voltage formed at the second terminal of the first switch to a periodic signal;
wherein the switching mode power converter further comprises;
a. a first energy storage device having a first terminal and a second terminal, wherein the first terminal of the first energy storage device is coupled to the second pin and wherein the regulated output is formed at the second terminal of the first energy storage device; and
b. a second energy storage device having a first terminal and a second terminal, wherein the first terminal of the second energy storage device is coupled to the second terminal of the first energy storage device and wherein the second terminal of the second energy storage device is coupled to the third pin.
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Accused Products
Abstract
A controlled output voltage is provided for a switching mode power converter operating in the continuous conduction mode without requiring a feedback path coupled to monitor the output voltage. Instead, a voltage related to the input voltage is monitored. The monitored voltage is compared to a periodic waveform for forming a switch control signal. In the case of a buck converter operating as a voltage regulator, over each period of the periodic waveform, the periodic waveform is representative of the inverse function. In the case of a boost converter operating as a voltage regulator or buck converter operating as a bus terminator or power amplifier, over each period of the periodic waveform, the periodic waveform has a linear slope. The switch control signal controls a duty cycle of the power switches. Therefore, switching is controlled in an open loop, rather than in a closed loop. By monitoring a voltage related to the input voltage, rather than the output voltage, an integrated circuit for controlling the buck converter or boost converter requires few pins and can sink or source current.
222 Citations
41 Claims
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1. A switching mode power converter including an integrated circuit controller, wherein none of the pins of the integrated circuit controller are coupled to monitor a regulated output of the power converter, the integrated circuit controller comprising:
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a. a first pin coupled to a first terminal of a first switch; b. a second pin coupled to a second terminal of the first switch and to a first terminal of a second switch; c. a third pin coupled to a second terminal of the second switch; and d. a circuit coupled to control the first switch and the second switch by comparing a signal proportional to a voltage formed at the second terminal of the first switch to a periodic signal; wherein the switching mode power converter further comprises; a. a first energy storage device having a first terminal and a second terminal, wherein the first terminal of the first energy storage device is coupled to the second pin and wherein the regulated output is formed at the second terminal of the first energy storage device; and b. a second energy storage device having a first terminal and a second terminal, wherein the first terminal of the second energy storage device is coupled to the second terminal of the first energy storage device and wherein the second terminal of the second energy storage device is coupled to the third pin. - View Dependent Claims (2)
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3. A switching mode power converter for providing an output voltage at an output node from an input voltage source, the power converter comprising:
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a. a first switch for storing energy from the input source in an energy storage device; b. a second switch for discharging the energy storage device, the second switch coupled to the first switch; and c. a control circuit for controlling switching of the first switch and the second switch in an open loop based upon a level of the input voltage source wherein the control circuit compares a signal representative of the level of the input voltage source to a periodic waveform for controlling said switching. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A switching mode power converter for providing an output voltage at an output node from an input voltage source, the power converter comprising:
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a. a first switch having a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the input voltage source; b. an energy storage device having a first terminal and a second terminal wherein a first terminal of the energy storage device is coupled to the second terminal of the first switch and the second terminal of the energy storage device is coupled to the output node; c. a second switch having a first terminal, a second terminal and control terminal, wherein the first terminal of the second switch is coupled to the first terminal of the energy storage device and the second terminal is coupled to a ground node; d. a control circuit for controlling switching of the first switch and the second switch by monitoring a level of voltage at the first terminal of the energy storage device, the control circuit coupled to the control terminal of the first switch, to the control terminal of the second switch and coupled to the first terminal of the energy storage device, wherein the control circuit comprises; i. a comparator having a first input terminal, a second input terminal and an output terminal wherein the first input terminal of the comparator is coupled to the first terminal of the energy storage device; ii. a generator for generating a periodic waveform at a first output terminal and a clock signal a second output terminal wherein the first output terminal of the generator is coupled to the second input terminal of the comparator; and iii. a flip-flop having a first input, a second input and an output terminal wherein the first input of the flip-flop is coupled to the output terminal of the comparator, the second input of the flip-flop is coupled to the second output terminal of the generator and the output terminal of the flip-flop is coupled to control switching. - View Dependent Claims (19, 20, 21)
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22. A switching mode power converter for providing an output voltage at an output node from an input voltage source, the power converter comprising:
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a. a first switch having a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the input voltage source; b. an energy storage device having a first terminal and a second terminal wherein a first terminal of the energy storage device is coupled to the second terminal of the first switch and the second terminal of the energy storage device is coupled to the output node; c. a second switch having a first terminal, a second terminal and control terminal, wherein the first terminal of the second switch is coupled to the first terminal of the energy storage device and the second terminal is coupled to a ground node; d. a control circuit for controlling switching of the first switch and the second switch by monitoring a level of voltage at the first terminal of the energy storage device, the control circuit coupled to the control terminal of the first switch, to the control terminal of the second switch and coupled to the first terminal of the energy storage device, wherein the control circuit compares a signal representative of the level of voltage at the first terminal of the energy storage device to a periodic waveform for controlling switching. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A switching mode power converter including an integrated circuit controller, the integrated circuit controller comprising:
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a. a first pin coupled to a first terminal of a first switch; b. a second pin coupled to a second terminal of the first switch and to a first terminal of a second switch; c. a third pin coupled to a second terminal of the second switch; and d. a circuit coupled to control the first switch and the second switch by comparing a signal proportional to a voltage formed at the second terminal of the first switch to a periodic signal wherein the voltage formed at the second terminal of the first switch is representative of an input voltage applied to the first pin when the first switch is closed. - View Dependent Claims (33, 34, 35)
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36. A switching mode power converter including an integrated circuit controller, the integrated circuit controller comprising:
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a. a first pin coupled to a first terminal of a first switch; b. a second pin coupled to a second terminal of the first switch and to a first terminal of a second switch; c. a third pin coupled to a second terminal of the second switch; and d. a circuit coupled to control the first switch and the second switch by comparing a signal proportional to a voltage formed at the second terminal of the first switch to a periodic signal wherein the periodic signal is representative of 1/time vs. time over each period. - View Dependent Claims (37)
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38. A switching mode power converter for providing an output voltage at an output node from an input voltage source, the power converter comprising:
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a. a first switch for storing energy from the input source in an energy storage device; b. a second switch for discharging the energy storage device, the second switch coupled to the first switch; and c. a control circuit for controlling switching of the first switch and the second switch in an open loop based upon a level of the input voltage source wherein the output voltage is controlled without being sensed by the control circuit. - View Dependent Claims (39, 40, 41)
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Specification