Reference voltage generator with fast start-up and low stand-by power

Claim 2

A reference voltage generator comprising: a reference stage which generates a reference voltage signal; a controller coupled to the reference stage to receive the reference voltage signal, the controller generating a control signal responsive to the reference voltage signal; and a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal, the pull-up stage being capable of being switched off during normal operation; wherein the controller switches the pull-up stage off when the reference signal reaches a predetermined voltage.

Claim 3

A reference voltage generator according to claim 1 wherein the controller switches the pull-up stage on when power is applied to the reference voltage generator.

Claim 4

A reference voltage generator according to claim 1 wherein the controller includes a control voltage generator which generates a control voltage signal and a comparator coupled to the control voltage generator, the comparator generating an output signal responsive to the difference between the reference voltage signal and the control voltage signal.

Claim 5

A reference voltage generator 3 wherein the comprising: a reference stage which generates a reference voltage signal: a controller coupled to the reference stage to receive the reference voltage signal, the controller generating a control signal responsive to the reference voltage signal; and a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal: wherein the controller includes: a control voltage generator which generates a control voltage signal: a comparator coupled to the control voltage generator the comparator generating an output signal responsive to the difference between the reference voltage signal and the control voltage signal: a latch coupled to the comparator for latching the output signal from the comparator, thereby generating a level detection signal; and a flip-flop coupled to the latch, the flip-flop generating the control signal responsive to the level detection signal.

Claim 6

A reference voltage generator 3 wherein the comprising: a reference stage which generates a reference voltage signal: a controller coupled to the reference stage to receive the reference voltage signal, the controller generating a control signal responsive to the reference voltage signal; and a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal: wherein the controller includes: a control voltage generator which generates a control voltage signal: a comparator coupled to the control voltage generator the comparator generating an output signal responsive to the difference between the reference voltage signal and the control voltage signal: a latch coupled to the comparator for latching the output signal from the comparator, thereby generating a level detection signal; and a flip-flop coupled to the latch, the flip-flop generating the control signal responsive to the level detection signal.

Claim 7

A reference voltage generator comprising: a reference stage which generates a reference voltage signal; a controller coupled to the reference stage to receive the reference voltage signal, the controller generating a control signal responsive to the reference voltage signal: and a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal; wherein the controller includes: a control voltage generator which generates a control voltage signal; a comparator coupled to the control voltage generator the comparator generating an output signal responsive to the difference between the reference voltage signal and the control voltage signal; and a flip-flop which disables the comparator and control voltage generator responsive to the output signal from the comparator.

Claim 8

A reference voltage generator comprising: a reference stage which generates a reference voltage signal; a controller coupled to the reference stage to receive the reference voltage signal, the controller generating a control signal responsive to the reference voltage signal: and a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal; wherein the controller includes: a control voltage generator which generates a control voltage signal; a comparator coupled to the control voltage generator the comparator generating an output signal responsive to the difference between the reference voltage signal and the control voltage signal; and a flip-flop which disables the comparator and control voltage generator responsive to the output signal from the comparator.

Claim 9

A reference voltage generator according to claim 5 wherein the flip-flop enables the comparator and control voltage generator responsive to a boost signal.

Claim 10

A reference voltage generator according to claim 1 further including a first power supply node, a second power supply node, a reference node, and a control node, the reference stage generating the reference voltage signal at the reference node, the controller generating the control signal at the control node.

Claim 11

A reference voltage generator 7 comprising: a reference stage which generates a reference voltage signal: a controller coupled to the reference stage to receive the reference voltage signal the controller generating a control signal responsive to the reference voltage signal: a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal: a first power supply node: a second power supply node; a reference node: and wherein the reference stage generates the reference voltage signal at the reference node, and the controller generates the control signal at the control node, and wherein the pull-up stage includes a transistor having a source coupled to the first power supply node, a drain coupled to the reference node, and a gate coupled to the control node, whereby the transistor pulls up the reference voltage signal responsive to the control signal at the control node.

Claim 12

A reference voltage generator 7 comprising: a reference stage which generates a reference voltage signal: a controller coupled to the reference stage to receive the reference voltage signal the controller generating a control signal responsive to the reference voltage signal: a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal: a first power supply node: a second power supply node; a reference node: and wherein the reference stage generates the reference voltage signal at the reference node, and the controller generates the control signal at the control node, and wherein the pull-up stage includes a transistor having a source coupled to the first power supply node, a drain coupled to the reference node, and a gate coupled to the control node, whereby the transistor pulls up the reference voltage signal responsive to the control signal at the control node.

Claim 13

A reference voltage generator 7 comprising: a reference stage which generates a reference voltage signal; a controller coupled to the reference stage to receive the reference voltage signal, the controller generating a control signal responsive to the reference voltage signal; a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal; a first power supply node; a second power supply node: a reference node: and a control node: wherein the reference stage generates the reference voltage signal at the reference node, and the controller generates the control signal at the control node; and wherein the controller includes a control voltage generator including a first transistor having a source coupled to the first power supply node, a drain coupled to a control voltage node, and a gate coupled to the second power supply node, and a second transistor having a source coupled to the second power supply node, a drain coupled to the control voltage node, and a gate coupled to the first power supply node.

Claim 14

A reference voltage generator 7 comprising: a reference stage which generates a reference voltage signal; a controller coupled to the reference stage to receive the reference voltage signal, the controller generating a control signal responsive to the reference voltage signal; a pull-up stage coupled to the controller to receive the control signal and coupled to the reference stage to pull up the reference voltage signal responsive to the control signal; a first power supply node; a second power supply node: a reference node: and a control node: wherein the reference stage generates the reference voltage signal at the reference node, and the controller generates the control signal at the control node; and wherein the controller includes a control voltage generator including a first transistor having a source coupled to the first power supply node, a drain coupled to a control voltage node, and a gate coupled to the second power supply node, and a second transistor having a source coupled to the second power supply node, a drain coupled to the control voltage node, and a gate coupled to the first power supply node.

Claim 15

A reference voltage generator according to claim 9 wherein the controller further includes a comparator having a first input terminal coupled to the reference node, a second input terminal coupled to the control voltage node, and an output terminal coupled to the control node.

Claim 16

A reference voltage generator according to claim 10 wherein the controller further includes a latch including a fast inverter having an input terminal coupled to the output terminal of the comparator and an output terminal coupled to a level detection node, and a second inverter having an output terminal coupled to the input terminal of the first inverter and an output terminal coupled to the input terminal of the first inverter.

Claim 17

A reference voltage generator according to claim 11 wherein the controller further includes a flip-flop including a first NAND gate having a first input terminal coupled to the level detection node, a second input terminal coupled to an output terminal of a second NAND gate, and an output terminal coupled to the control node, the second NAND gate having a first input terminal coupled to a boost voltage node and a second input terminal coupled to the control node.

Claim 18

A reference voltage generator according to claim 12 wherein the comparator has a sink current terminal and the controller further includes a fast switching transistor having a source coupled to the second power supply node, a drain coupled to the sink current terminal, and a gate coupled to the output terminal of the second NAND gate, and a second switching transistor having a source coupled to the second power supply node, a drain coupled to the source of the second transistor of the control voltage generator, and a gate coupled to the output terminal of the second NAND gate.

Claim 19

A reference voltage generator according to claim 12 further including a boost voltage circuit including: a first transistor having a source coupled to the first power supply node, a drain coupled to the second power supply node through a resistor, and a gate coupled to the second power supply node through a capacitor; a second transistor having a drain coupled to the fast power supply node, a source coupled to the gate of the fast transistor, and a gate coupled to the gate of the first transistor; a first inverter having an input terminal coupled to the source of the second transistor; and a second inverter having an input terminal coupled to the output terminal of the first inverter and an output terminal coupled to the boost voltage node.

Claim 20

A reference voltage generator comprising: means for generating a reference voltage signal; means for generating a control signal responsive to the reference voltage signal; and means for pulling up the reference voltage signal responsive to the control signal, said means being capable of being switched off during normal operation: wherein the means for generating a control signal switches off the means for pulling up the reference voltage sisal when the reference voltage signal reaches a predetermined voltage.

Claim 21

A reference voltage generator comprising: means for generating a reference voltage signal; means for generating a control signal responsive to the reference voltage signal; and means for pulling up the reference voltage signal responsive to the control signal, said means being capable of being switched off during normal operation: wherein the means for generating a control signal switches off the means for pulling up the reference voltage sisal when the reference voltage signal reaches a predetermined voltage.

Claim 22

A reference voltage generator according to claim 15, wherein the means for generating a control signal can be disabled responsive to a boost signal.

Claim 25

A method according to claim 17 further including: enabling a control voltage generator when the power is applied, thereby generating a control voltage signal; and comparing the control voltage signal to the reference voltage signal.

Claim 26

A method according to claim 18 further including disabling the control voltage generator when the voltage of the reference voltage signal equals the voltage of the control voltage signal.