Divide-add circuit and high-resolution digital-to-analog converter using the same

• US 7,283,077 B2
• Filed: 04/06/2006
• Issued: 10/16/2007
• Est. Priority Date: 05/19/2005
• Status: Expired due to Fees

• Current Assignee: i-KAIST Co., Ltd.
• Original Assignee: Korea Advanced Institute of Science and Technology
• Inventors: Kim, Sang-Kyung, Son, Young-Suk, Cho, Gyu-Hyeong
• Primary Examiner(s): Mai; Lam T.
• Application Number:
  US11/398,868
• Publication Number:
  US 20060261998A1
• Time in Patent Office: 558 Days
• Field of Search: 341140-172
• US Class Current: 341/150
• CPC Class Codes: H03M 1/667 Recirculation type
• CPC Class Codes: H03M 1/682 both converters being of the unary decoded type

Abstract

Disclosed herein is a divide-add circuit and a high-resolution Digital-to-Analog Converter (DAC) using the same. The DAC includes a plurality of DAC units and one or more divide-add circuit units. The plurality of DAC units performs Digital-Analog (DA) conversion on two or more segmented codes, into which an input digital code is segmented. The one or more divide-add circuit units is configured to be each composed only of capacitors and switches and to generate a final DA conversion output for the entire input digital code based on the voltages of the DAC units. Accordingly, a high resolution of more than ten bits can be implemented.

Claims

1. A divide-add circuit, comprising:

a first capacitor configured to store charges depending on a first voltage across the first capacitor;

a third capacitor configured to store charges depending on a second voltage across the third capacitor;

a first path control switch connected to the third capacitor, and configured such that the first and third capacitors are connected in series to each other therethrough; and

a second capacitor connected in parallel to the first capacitor with respect to the first voltage, and configured to be connected in series to the third capacitor though the first path control switch;

wherein a value of voltage, which is obtained by dividing the second voltage at an appropriate ratio that is proportional to a ratio of the second and third capacitors, is added to the first voltage, prior to connection between the second and third capacitors; and

wherein a value of the first voltage across the first capacitor is calculated by a division and addition operation in a state in which the second capacitor is connected in series to the third capacitor through the first path control switch and the first and third capacitors are connected in parallel to each other.

2. The divide-add circuit as set forth in claim 1, wherein the second capacitor is connected with a second path control switch that is turned off when the first path control switch is turned on, thereby allowing the second capacitor and the third capacitor to be connected in series to each other.

3. The divide-add circuit as set forth in claim 1, wherein the first and third capacitors have identical capacitance, and capacitance of the second capacitor is smaller than the capacitance of the first or third capacitor.

4. A high-resolution Digital-to-Analog Converter (DAC) using a divide-add circuit, comprising:

a plurality of DAC units for performing Digital-Analog (DA) conversion on two or more segmented codes, into which an input digital code is segmented; and

at least one divide-add circuit unit to generate a final DA conversion output for the entire input digital code based on the voltages of the DAC units, each of said at least one divide-add circuit units consisting of capacitors and switches.

5. The high-resolution DAC as set forth in claim 4, wherein each of the DAC units is a DAC unit that has an output corresponding to voltage of the capacitors.

6. The high-resolution DAC as set forth in claim 4, wherein the DAC units are connected in parallel to each other.

7. The high-resolution DAC as set forth in claim 4, wherein the DAC units are algorithmic DACs or cyclic DACs.

8. The high-resolution DAC as set forth in claim 4, wherein the at least one divide-add circuit units are a plurality of divide-add circuit units that adds conversion results of the DAC units that perform DA conversion on the segmented codes, ranging from a segmented code including a Least Significant Bit (LSB) of the input digital code to a segmented code including a Most Significant Bit (MSB) of the input digital code, and obtains a DA conversion result of the entire input digital code.

9. The high-resolution DAC as set forth in claim 8, wherein each of the at least one divide-add circuit units comprises:

a first capacitor configured to store charges depending on a first voltage across the first capacitor;

a third capacitor configured to store charges depending on a second voltage across the third capacitor;

a first path control switch connected to the third capacitor, and configured such that the first and third capacitors are connected in series to each other therethrough; and

a second capacitor connected in parallel to the first capacitor with respect to the first voltage, and configured to be connected in series to the third capacitor though the first path control switch;

wherein a value of voltage, which is obtained by dividing the second voltage at an appropriate ratio that is proportional to a ratio of the second and third capacitors, is added to the first voltage, prior to connection between the second and third capacitors; and

wherein a value of the first voltage across the first capacitor is calculated by a division and addition operation in a state in which the second capacitor is connected in series to the third capacitor through the first path control switch and the first and third capacitors are connected in parallel to each other.

10. The high-resolution DAC as set forth in claim 9, wherein the second capacitor is connected with a second path control switch that is turned off when the first path control switch is turned on, thereby allowing the second capacitor and the third capacitor to be connected in series to each other.

11. The high-resolution DAC as set forth in claim 9, wherein the first and third capacitors have identical capacitance, and capacitance of the second capacitor is smaller than the capacitance of the first or third capacitor.

12. A high-resolution Digital-to-Analog Converter (DAC) using a divide-add circuit, comprising:

a plurality of DAC units for performing Digital-Analog (DA) conversion on two or more segmented codes, into which an input digital code is segmented; and

one or more divide-add circuit units configured to be each composed only of capacitors and switches and to generate a final DA conversion output for the entire input digital code based on the voltages of the DAC units,

wherein the one or more divide-add circuit units are a plurality of divide-add circuit units that adds conversion results of the DAC units that perform DA conversion on the segmented codes, ranging from a segmented code including a Least Significant Bit (LSB) of the input digital code to a segmented code including a Most Significant Bit (MSB) of the input digital code, and obtains a DA conversion result of the entire input digital code.

13. The high-resolution DAC as set forth in claim 12, wherein each of the DAC units is a DAC unit that has an output corresponding to voltage of the capacitors.

14. The high-resolution DAC as set forth in claim 12, wherein the DAC units are connected in parallel to each other.

15. The high-resolution DAC as set forth in claim 12, wherein the DAC units are algorithmic DACs or cyclic DACs.

16. The high-resolution DAC as set forth in claim 12, wherein each of the one or more divide-add circuit units comprises:

a first capacitor configured to store charges depending on a first voltage across the first capacitor;

a third capacitor configured to store charges depending on a second voltage across the third capacitor;

a first path control switch connected to the third capacitor, and configured such that the first and third capacitors are connected in series to each other therethrough; and

a second capacitor connected in parallel to the first capacitor with respect to the first voltage, and configured to be connected in series to the third capacitor though the first path control switch;

wherein a value of voltage, which is obtained by dividing the second voltage at an appropriate ratio that is proportional to a ratio of the second and third capacitors, is added to the first voltage, prior to connection between the second and third capacitors; and

wherein a value of the first voltage across the first capacitor is calculated by a division and addition operation in a state in which the second capacitor is connected in series to the third capacitor through the first path control switch and the first and third capacitors are connected in parallel to each other.

17. The high-resolution DAC as set forth in claim 12, wherein the second capacitor is connected with a second path control switch that is turned off when the first path control switch is turned on, thereby allowing the second capacitor and the third capacitor to be connected in series to each other.

18. The high-resolution DAC as set forth in claim 12, wherein the first and third capacitors have identical capacitance, and capacitance of the second capacitor is smaller than the capacitance of the first or third capacitor.

19. The high-resolution DAC as set forth in claim 12, further comprising a control unit for segmenting the input digital code into a plurality codes.