Configurable voltage generator

• US 20050174162A1
• Filed: 02/09/2004
• Published: 08/11/2005
• Est. Priority Date: 02/09/2004
• Status: Abandoned Application

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Cheng, Tung-Shuan, Hwang, Wei, Liao, Hung-Jen
• Application Number:
  US10/775,731
• Publication Number:
  US 20050174162A1
• Time in Patent Office: Days
• US Class Current: 327/535
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

A configurable voltage generator is disclosed for generating multiple levels of output. It includes an oscillator module for generating a pumping signal, a digital to analog (D/A) converter coupled to the oscillator for generating one or more analog signals of a predetermined voltage level based on the pumping signal as configured by a set of inputs thereof, and a charge pump coupled to the D/A converter for producing a direct current (DC) output based on the analog signals generated by the D/A converter.

Claims

1. A configurable voltage generator comprising:

an oscillator module for generating a pumping signal;

a digital to analog (D/A) converter coupled to the oscillator for generating an analog signal of a predetermined voltage level based on the pumping signal as configured by a set of inputs thereof; and

a charge pump coupled to the D/A converter for producing a direct current (DC) output based on the analog signals generated by the D/A converter,

wherein said direct current output is configurable by adjusting the inputs of the D/A converter.

2. The generator of claim 1 further comprising a load capacitor coupled to the charge pump for smoothing the output.

3. The generator of claim 1 wherein the oscillator is a ring oscillator.

4. The generator of claim 3 wherein the pumping signal is a square wave signal.

5. The generator of claim 4 wherein a voltage swing of the square wave signal is within a predetermined operating voltage range.

6. The generator of claim 1 wherein the charge pump is a negative charge pump for generating at least one configurable negative output to be used as a substrate-bias voltage for reducing leakage of a semiconductor device.

7. The generator of claim 1 further comprising a recovery module for clearing the output before generating a new value.

8. The generator of claim 1 wherein the D/A converter further includes an initial control module for initializing the D/A converter.

9. The generator of claim 8 wherein the D/A converter further includes a code converter for transforming the inputs to a set of thermometer signals.

10. The generator of claim 1 wherein the D/A converter is selected with a predetermined number of inputs based on a predetermined number of steps needed for the analog signals generated.

11. The generator of claim 1 wherein the charge pump is a voltage doubler producing the output as a sum of a voltage output swing of the D/A converter and a supply voltage.

12. A configurable voltage generator for providing a substrate-bias voltages for reducing leakage current, the generator comprising:

an oscillator module for generating a square wave pumping signal;

a digital to analog (D/A) converter coupled to the oscillator for generating an analog signal of a predetermined voltage level based on the pumping signal as configured by a set of inputs thereof; and

a negative charge pump coupled to the D/A converter for producing a direct current (DC) output based on the analog signals generated by the D/A converter.

13. The generator of claim 12 further comprising a load capacitor coupled to the negative charge pump for smoothing the output.

14. The generator of claim 12 wherein a voltage swing of the square wave pumping signal is within a predetermined operating voltage range.

15. The generator of claim 12 further comprising a recovery module for clearing the output before generating a new value.

16. The generator of claim 12 wherein the D/A converter is selected with a predetermined number of inputs based on a predetermined number of steps needed for the analog signals generated.

17. A method for producing one or more voltages by a configurable voltage generator for providing one or more substrate-bias voltages for reducing leakage current, the method comprising:

activating an oscillator module for generating a square wave pumping signal;

selecting a set of inputs to a digital to analog (D/A) converter coupled to the oscillator for generating an analog signal of a predetermined voltage level based on the pumping signal; and

wherein a negative charge pump coupled to the D/A converter produces a direct current (DC) output based on the analog signals generated by the D/A converter as configured by the selected inputs.

18. The method of claim 17 further comprising smoothing the output by a load capacitor coupled to the negative charge pump.

19. The method of claim 17 further comprising clearing the output before generating a new value.

20. The method of claim 17 further comprising determining a desired substrate-bias voltage based on an optimal effect on the leakage current.