Word-line driver using level shifter at local control circuit

• US 8,427,888 B2
• Filed: 02/09/2010
• Issued: 04/23/2013
• Est. Priority Date: 02/09/2010
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Lu, Chung-Ji, Liao, Hung-Jen, Cheng, Hong-Chen, Wu, Chung-Yi, Chandra, Uppu Sharath, Chen, Hsu-Shun, Hung, Lee-Cheng
• Primary Examiner(s): Ho, Hoai V
• Assistant Examiner(s): Graham, Kretelia
• Application Number:
  US12/702,594
• Publication Number:
  US 20110194362A1
• Time in Patent Office: 1,169 Days
• Field of Search: 365/189.11, 365/189.09, 365/230.06, 365/185.23, 365/185.25, 365/185.18
• US Class Current: 365/189.11
• CPC Class Codes: G11C 8/08 Word line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, for word lines
• CPC Class Codes: G11C 8/10 Decoders

Abstract

A representative circuit device includes a local control circuit having a level shifter, wherein in response to receipt of a first address signal the level shifter shifts the first address signal from a first voltage level to a second voltage level, providing a level shifted first address signal; and a word-line driver having at least one input for receiving a plurality of address signals, wherein the at least one input includes a first input that is coupled to the local control circuit to receive the level shifted first address signal, and an output that is electrically coupled to a word line of a memory cell array.

Claims

1. A circuit device comprising:

a local control circuit having a level shifter configured to shift a first address signal received from a main control circuit from a first voltage level to a second voltage level to provide a level shifted first address signal; and

a word-line driver configured to receive at least one signal from the main control circuit and to receive the level shifted first address signal from the local control circuit, and the word line driver including an output that is electrically coupled to a word line of a memory cell array,

wherein the word-line driver includes at least two-gate delays comprising a first gate having a first transistor for receiving the level shifted first address signal from the level shifter and a second transistor for receiving the first address signal, which reduces gate delay from the level shifter,

wherein the second transistor is provided between a power supply terminal and an output of the first gate and is coupled in series with the first transistor, and

wherein the first gate includes the second transistor that, when outputting a low signal responsive to receiving a high signal from the first address signal, turns off prior to the first transistor to reduce the gate delay from the level shifter.

4. The circuit device of claim 1, wherein the word-line driver is a four-gate delay word-line driver.

5. The circuit device of claim 4, wherein the four-gate delay word-line driver includes a decoder stage that includes a second gate and a third gate to receive second and third address signals of a plurality of address signals received at the four-gate delay word-line driver.

6. The circuit device of claim 5, wherein the four-gate delay word-line driver reduces gate delay from the level shifter and includes a fourth gate having a third transistor and a first inverter to receive the level shifted first address signal, wherein the third gate outputs a low signal responsive to receiving a high signal from the first address signal.

7. The circuit device of claim 6, wherein the four-gate delay word-line driver further includes a fourth gate having an inverter to receive the output of the third gate, wherein an output of the fourth gate is electrically coupled to the word line of the memory cell array.

8. The circuit device of claim 1, wherein the word-line driver includes inputs for receiving second and third address signals from the main control circuit.

10. The memory circuit of claim 1, wherein word-line driver includes a second gate having an inverter to receive the output of the first gate, wherein an output of the second gate is electrically coupled to the word line of the memory cell array.

2. A circuit device, comprising:

a local control circuit having a level shifter, wherein in response to receipt of a first address signal the level shifter shifts the first address signal from a first voltage level to a second voltage level, providing a level shifted first address signal; and

a two-gate delay word-line driver having at least one input for receiving a plurality of address signals, wherein the at least one input includes a first input that is coupled to the local control circuit to receive the level shifted first address signal, and an output that is electrically coupled to a word line of a memory cell array,

wherein the two-gate delay word-line driver reduces gate delay from the level shifter and includes a first gate having a first transistor to receive the level shifted first address signal from the level shifter and a second transistor to receive the first address signal, wherein the first gate outputs a low signal responsive to receiving a high signal from the first address signal.

3. The circuit device of claim 2, wherein the two-gate delay word-line driver further includes a second gate having an inverter to receive the output of the first gate, wherein an output of the second gate is electrically coupled to the word line of the memory cell array.

9. A memory circuit comprising:

a local control circuit having a level shifter for shifting a first address signal received from a main control circuit from a first voltage level to a second voltage level to provide a level shifted first address signal;

a word-line driver configured to receive the level shifted address signal from the level shifter and a plurality of address signals from the main control circuit; and

a memory cell array having a word line that is coupled to an output of the word-line driver,

wherein the world-line driver is a two-gate delay word-line driver comprising a first gate having a first transistor for receiving the level shifted first address signal from the level shifter and a second transistor for receiving the first address signal, which reduces gate delay from the level shifter,

wherein the second transistor is provided between a power supply terminal and an output of the first gate and is coupled in series with the first transistor, and

wherein the first gate includes the second transistor that, when outputting a low signal responsive to receiving a high signal from the first address signal, turns off prior to the first transistor to reduce the gate delay from the level shifter.

11. A memory circuit, comprising:

a local control circuit having a level shifter, wherein in response to receipt of a first address signal the level shifter shifts the first address signal from a first voltage level to a second voltage level, providing a level shifted first address signal;

a four-gate delay word-line driver having at least one input for receiving a plurality of address signals, wherein the at least one input includes a first input to receive the level shifted address signal from the level shifter; and

a memory cell array having a word line that is coupled to an output of the word-line driver, wherein the four-gate delay word-line driver includes a decoder stage that includes a first gate and second gate to receive second and third address signals of the plurality of address signals,

wherein the four-gate delay word-line driver reduces gate delay from the level shifter and includes a third gate having a first transistor to receive the first address signal from the level shifter and a first inverter to receive the first address signal, wherein the third gate outputs a low signal responsive to receiving a high signal from the first address signal.

12. The memory circuit of claim 11, wherein the four-gate delay word-line driver further includes a fourth gate having an inverter to receive the output of the third gate, wherein an output of the fourth gate is electrically coupled to the word line of the memory cell array.