Cascode regulator with plural outputs
First Claim
1. A cascode circuit for generating a regulated voltage from a supply voltage, comprising:
- at least first and second regulator circuits being coupled in a cascode configuration for generating a regulated voltage, each regulator circuit including;
a driver for generating a drive signal;
a charge pump having a first voltage input coupled to a first voltage source, being responsive to the drive signal, to provide a pump voltage that is boosted from a voltage level of the first voltage source;
a voltage buffer coupled between a supply voltage source and the charge pump for generating an output voltage corresponding to the pump voltage;
an amplifier having a reference input coupled to a reference voltage, a sense input coupled to a sense signal representative of the pump voltage, and an output, operable in response to a difference between the reference voltage and the sense signal, to control the driver; and
a switch being coupled from the amplifier output to an output of the charge pump such that the pump voltage is controllably boosted by the amplifier output through the switch.
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Accused Products
Abstract
The present invention provides a circuit and method having a fast response time for generating a regulated voltage from a first voltage source. The circuit includes a driver for generating a drive signal. The driver has a clock input coupled to a clock signal. A charge pump that has a first voltage input coupled to the first voltage source. In response to the drive signal, the charge pump provides a pump voltage that is boosted from the first voltage. An amplifier has a reference input coupled to a reference voltage, a sense input coupled to a sense signal representative of the pump voltage, and an output. The amplifier is operable in response to a difference between the reference voltage and the sense signal, to control the driver. A switch is coupled from the amplifier output to an output of the charge pump such that the pump voltage is controllably boosted by the amplifier output through the switch. In another aspect of the invention the circuit is arranged in a cascode configuration to provide a low noise output voltage. The cascode configuration can provide a low noise output having an increased ripple frequency and reduced ripple amplitude. In addition, in another aspect of the invention, the cascode configuration can provide an output voltage level that is not limited by the level of the supply voltage.
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Citations
25 Claims
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1. A cascode circuit for generating a regulated voltage from a supply voltage, comprising:
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at least first and second regulator circuits being coupled in a cascode configuration for generating a regulated voltage, each regulator circuit including;
a driver for generating a drive signal;
a charge pump having a first voltage input coupled to a first voltage source, being responsive to the drive signal, to provide a pump voltage that is boosted from a voltage level of the first voltage source;
a voltage buffer coupled between a supply voltage source and the charge pump for generating an output voltage corresponding to the pump voltage;
an amplifier having a reference input coupled to a reference voltage, a sense input coupled to a sense signal representative of the pump voltage, and an output, operable in response to a difference between the reference voltage and the sense signal, to control the driver; and
a switch being coupled from the amplifier output to an output of the charge pump such that the pump voltage is controllably boosted by the amplifier output through the switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A cascode circuit for generating a regulated voltage from a supply voltage, comprising:
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at least first and second regulator means being coupled in a cascode configuration for generating a regulated voltage, each regulator circuit including;
driver means for generating a drive signal;
charge pump means for generating a pump voltage, from a first voltage source, in response to the drive signal;
voltage buffer means for generating an output voltage corresponding to the pump voltage;
amplifier means for controlling the driver in response to a reference voltage and a sense signal representative of the pump voltage; and
switch means for providing a path through which the pump voltage is controllably boosted by the amplifier means. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 25)
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20. A method of generating at least two regulated voltages, each comprising the steps of:
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generating a drive signal;
generating a pump voltage in response to the drive signal, the pump voltage being boosted from a first voltage source;
generating an output voltage corresponding to the pump voltage;
generating an error signal in response to determining a difference between a reference voltage and a sense signal representative of the output voltage;
controlling the drive signal in response to the error signal; and
applying a representation of the error signal to the pump voltage, such that the pump voltage is controllably boosted; and
coupling the at least two regulated voltages in a cascode configuration. - View Dependent Claims (21, 22, 23, 24)
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Specification