CHARGE PUMP HAVING RAMP RATE CONTROL
First Claim
1. A charge pump comprising:
- a first counter having a control input for receiving a control signal, and an output for providing a first count value, wherein the first count value is incremented in response to the control signal being a first logic state and the first count value is decremented in response to the control signal being a second logic state; and
a pump stage having a variable capacitor, the variable capacitor having a control input coupled to the output of the first counter for receiving the first count value, wherein a capacitance value of the variable capacitor is changed in response to the first count value changing, and wherein the capacitance value is for determining a ramp-up rate of an output voltage at an output of the charge pump.
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Accused Products
Abstract
A charge pump includes a first counter and a pump stage. The first counter has a control input for receiving a control signal, and an output for providing a first count value. The first count value is incremented in response to the control signal being a first logic state and the first count value is decremented in response to the control signal being a second logic state. The pump stage has a variable capacitor. The variable capacitor has a control input coupled to the output of the first counter for receiving the first count value. The capacitance value of the variable capacitor is changed in response to the first count value changing. The capacitance value is for determining a ramp-up rate of an output voltage at an output of the charge pump.
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Citations
20 Claims
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1. A charge pump comprising:
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a first counter having a control input for receiving a control signal, and an output for providing a first count value, wherein the first count value is incremented in response to the control signal being a first logic state and the first count value is decremented in response to the control signal being a second logic state; and a pump stage having a variable capacitor, the variable capacitor having a control input coupled to the output of the first counter for receiving the first count value, wherein a capacitance value of the variable capacitor is changed in response to the first count value changing, and wherein the capacitance value is for determining a ramp-up rate of an output voltage at an output of the charge pump. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A charge pump comprising:
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a first counter having an output for providing a first count value; a digital-to-analog converter having an input coupled to the output of the first counter, and an output for providing an analog representation of the first count value; a comparator having a first input coupled to the output of the digital-to-analog converter, a second input, and an output; a second counter having an input coupled to the output of the comparator, and an output for providing a second count value; and a pump stage having an input, an output coupled to the second input of the comparator, and a variable capacitor, a capacitance value of the variable capacitor being changed in response to the second count value. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A charge pump comprising:
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a first counter having an output for providing a first count value; a digital-to-analog converter having an input and an output; a first register for storing a digital value corresponding to a desired output voltage at an output of the charge pump; a switch having a first terminal coupled to the output of the first register, a second terminal coupled to the output of the first counter, and a third terminal coupled to the input of the digital-to-analog converter, wherein the digital value and the first count value are alternately provided to the input of the digital-to-analog converter in response to a clock signal; a comparator having a first input coupled to the output of the digital-to-analog converter, a second input, and an output; a second counter having an input coupled to the output of the comparator, and an output for providing a second count value; and a pump stage having a variable capacitor, the variable capacitor having an input coupled to the output of the second counter for receiving the second count value, the pump stage having an output coupled to the second input of the comparator, the pump stage having a clock input coupled to the output of the comparator. - View Dependent Claims (18, 19, 20)
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Specification