Digital to analog converter

Patent metadata

Field	Value
Publication number	US-9379725-B2
Application number	US-201514599608-A
Country	US
Kind code	B2
Filing date	Jan 19, 2015
Priority date	Oct 8, 2014
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A digital to analog converter may include a reference voltage generation unit that generates a reference voltage and a plurality of unit conversion units connected through an output node. The plurality of unit conversion units may set a voltage level of the output node in response to digital codes and the reference voltage.

First claim

What is claimed is:

1. A digital to analog converter comprising:
a reference voltage generation unit that generates a reference voltage; and
a plurality of unit conversion units, and a number of unit conversion units to be activated being decided in response to digital codes,
wherein the unit conversion units are deactivated or activated in response to digital codes, each activated unit conversion unit drives a control node to a voltage level corresponding to a voltage level of the reference voltage, and each deactivated unit conversion unit substantially maintains the control node to a voltage level greater than a voltage level of a ground voltage.

2. The digital to analog converter according to claim 1 , wherein the deactivated unit conversion unit is configured to substantially maintain the control node to the set voltage level between a voltage level of the control node of the activated unit conversion unit and the voltage level of the ground voltage.

3. The digital to analog converter according to claim 1 , wherein the deactivated unit conversion unit commonly electrically couples the control node and an output node.

4. The digital to analog converter according to claim 1 , wherein each of the plurality of unit conversion units receives each bit of the digital codes and is activated when one of the bits has a specific level.

5. The digital to analog converter according to claim 4 , wherein each of the plurality of unit conversion units comprises:
a voltage applying section that drives the control node in response to the voltage level of the reference voltage;
an output control section that electrically couples or separates the control node to/from the output node in response to the one of the bits; and
a voltage control section that controls the voltage level of the control node in response to the one of the bits.

6. The digital to analog converter according to claim 5 , wherein the output control section electrically couples the control node to the output node when the one of the bits has the specific level, and separates the control node from the output node when the one of the bits is not at the specific level.

7. The digital to analog converter according to claim 6 , wherein the voltage control section reduces the voltage level of the control node when the one of the bits does not have the specific level, and does not perform an operation for reducing the voltage level of the control node when the one of the bits has the specific level.

8. A digital to analog converter comprising:
a plurality of unit conversion units,
wherein a number of unit conversion units to be electrically coupled to an output node is decided in response to digital codes, and each of unit conversion units electrically coupled to the output node drives a control node to a voltage level corresponding to a voltage level of the reference voltage and electrically couples the control node to the output node, and each of unit conversion units not electrically coupled to the output node substantially maintains a voltage level of the control node to a voltage level greater than a voltage level of a ground voltage.

9. The digital to analog converter according to claim 8 , wherein a voltage level of the control node of the unit conversion unit not electrically coupled to the output node is a voltage level between the voltage level of the ground voltage and a voltage level of the control node of the unit conversion unit electrically coupled to the output node.

10. The digital to analog converter according to claim 9 , wherein each of the plurality of unit conversion units receives a bit of the digital codes and is electrically coupled to the output node when the bit for each of the plurality of unit conversion units has a specific level.

11. The digital to analog converter according to claim 10 , wherein each of the plurality of unit conversion units comprises:
a voltage applying section that drives the control node in response to the voltage level of the reference voltage;
an output control section that electrically couples or separates the control node to/from the output node in response to the bit; and
a voltage control section that controls the voltage level of the control node in response to the bit.

12. A digital to analog converter comprising:
first to third unit conversion units configured to be activated or deactivated in response to digital codes;
an activated unit conversion unit electrically coupled to an output node and configured to drive a control node to a voltage level corresponding to a voltage level of a reference voltage; and
a deactivated unit conversion unit configured to substantially maintain the control node to a voltage level greater than a ground voltage,
wherein the deactivated unit conversion unit is configured to substantially maintain the control node to a voltage level between a voltage level of the ground voltage and the voltage level of the control node.

13. The digital to analog converter according to claim 12 , further comprising:
a voltage control section configured to reduce the voltage level of the control node in response to one bit of digital codes.

14. The digital to analog converter according to claim 13 , further comprising:
an output control section configured to separate the control node from the output node in response to the one bit of the digital codes.

15. The digital to analog converter according to claim 13 , wherein the voltage control section is configured to reduce the voltage level of the control node when the one bit of the digital codes is at a specific level.

16. The digital to analog converter according to claim 13 , wherein the voltage control section is configured to substantially maintain the control node to a voltage less than the voltage level of the control node when the one bit of the digital codes is at a high level.

17. The digital to analog converter according to claim 13 , wherein the output control section electrically couples the control node to the output node in response to the one bit of the digital codes.

18. The digital to analog converter according to claim 12 , wherein the second and third unit conversion units are configured to not reduce internal voltage levels to the voltage level of the ground voltage.

19. The digital to analog converter according to claim 12 , wherein the first to third unit conversion units are electrically coupled to the output node.

20. The digital to analog converter according to claim 12 , further comprising:
a voltage control section configured to not reduce the voltage level of the control node according to one bit of digital codes.

Assignees

• Sk Hynix Inc

Inventors

• Ahn Chang Yong
• Cheon Jun Ho

Classifications

• H03M1/747

  with equal currents which are switched by unary decoded digital signals · CPC title

• H03M1/00

  Analogue/digital conversion; Digital/analogue conversion (conversion of analogue values to or from differential modulation H03M3/00) · CPC title

• H03M1/002 Primary

  Provisions or arrangements for saving power, e.g. by allowing a sleep mode, using lower supply voltage for downstream stages, using multiple clock domains or by selectively turning on stages when needed · CPC title

• H03M1/70

  Automatic control for modifying converter range · CPC title

• H03M1/745 Primary

  with weighted currents · CPC title