Current-sense type logic circuit and semiconductor integrated circuit using the same

• US 6,278,298 B1
• Filed: 08/09/1999
• Issued: 08/21/2001
• Est. Priority Date: 08/10/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hayakawa, Shigeyuki
• Primary Examiner(s): Tokar, Michael
• Assistant Examiner(s): PAIK, STEVEN SANGYUL
• Application Number:
  US09/369,896
• Time in Patent Office: 743 Days
• Field of Search: 326/115, 326/104, 326/112, 326/119, 326/121, 326/126-127, 327/55-56
• US Class Current: 326/119
• CPC Class Codes: H03K 19/08 using semiconductor devices H03K19/173 takes precedence; wherein the semiconductor devices are only diode rectifiers H03K19/12
• CPC Class Codes: H03K 19/0813 Threshold logic
• CPC Class Codes: H03K 19/23 Majority or minority circuits, i.e. giving output having the state of the majority or the minority of the inputs

Abstract

A logic circuit determines the logic based only on a change in electric current. The logic circuit comprises a logical value determination circuit, a reference current generator, and a current sense amplifier. The logical value determination circuit defines a logical current flowing in response to multiple logic-signals. The reference current generator produces a reference current which is used to determine whether the logical current defined by the logical value determination circuit is true or false. The current sense amplifier detects and amplifies a difference between the logic current and the reference current.

Claims

1. A current-sense type logic circuit comprising:

a logical value determination circuit configured to define a logical value and having a plurality of logic determination elements that define multiple electric paths extending in parallel between a logic node and a standard voltage source, each logic determination element having a control electrode configured to receive a logic input signal, and each electric path being controlled by an associated control electrode thereof based on the logic input signal applied to the control electrode;

a reference current generator configured to produce a reference current which is used to determine a logic; and

a current sense amplifier configured to detect and amplify a difference between the reference current and an electric current flowing through the logical value determination circuit corresponding to the logical value.

2. The current-sense type logic circuit according to claim 1, wherein the current sense amplifier comprises:

first and second output nodes;

a first load connected between a voltage source and the first output node;

a first driving transistor connected between the first output node and the logical value determination circuit, the gate of the first driving transistor being connected to the second output node;

a second load connected between the voltage source and the second output node; and

a second driving transistor connected between the second output node and the reference current generator, the gate of the second driving transistor being connected to the first output node.

3. The current-sense type logic circuit according to claim 2, wherein the logic node is connected to the first output node of the current sense amplifier.

4. The current-sense type logic circuit according to claim 3, wherein one or more logic determination elements are inserted in series in each of the electric paths between the logic node and the standard voltage.

5. The current-sense type logic circuit according to claim 4, wherein the reference current generator comprises one or more reference current generating elements, said one or more reference current generating elements being connected in series and defining an electric path with a cross-section smaller than the cross-section of a minimum-current electric path, through which the minimum current flows in the logical value determination circuit.

6. The current-sense type logic circuit according to claim 5, wherein the reference current generating elements and the logical value determination elements are insulating-gate field effect transistors, and the channel width of the reference current generating elements is about one half of the channel width of the logical value determination elements.

7. The current-sense type logic circuit according to claim 2, wherein the current sense amplifier further comprise:

a voltage sense amplifier detecting a current difference between the currents output from the first and second output nodes and amplifying the current difference as a voltage difference; and

an inverter for enhancing and inverting the logical value output from the voltage sense amplifier.

8. The current-sense type logic circuit according to claim 3, wherein the reference current generator produces a reference current which lies between an electric current of zero level and a minimum current that can flow through the electric paths according to the logical value defined by the logical value determination circuit.

9. The current-sense type logic circuit according to claim 1, wherein the reference current generator produces a reference current which lies between a current corresponding to a true value and a current corresponding to a false value of the logical value determination circuit.

10. The current-sense type logic circuit according to claim 1, wherein the current sense amplifier is a latch-type current sense amplifier.

11. The current-sense type logic circuit according to claim 10, wherein the latch-type current sense amplifier comprises:

a latch circuit having first and second input nodes and first and second output nodes;

a first activation insulating-gate field effect transistors connected between the first input node of the latch circuit and the logical value determination circuit;

a second activation insulating-gate field effect transistors connected between the second input node of the latch circuit and the reference current generator;

a first precharge insulating-gate field effect transistors connected between the first output node of the latch circuit and an operational voltage source; and

a second precharge insulating-gate field effect transistors connected between the second output node of the latch circuit and the operational voltage source.

12. The current-sense type logic circuit according to claim 11, wherein the reference current generator comprises one or more reference current generating elements, said one or more reference current generating elements being connected in series and defining an electric path with a cross-section smaller than the cross-section of a minimum-current electric path through which the minimum current flows in the logical value determination circuit, and wherein the current-sense type logic circuit further comprises:

a first dummy circuit connected to the first input node of the latch circuit of the latch-type current sense amplifier in parallel to the logical value determination circuit, the first dummy circuit having substantially the same structure as the reference current generator; and

a second dummy circuit connected to the second output node of the latch circuit in parallel to the reference current generator, the second dummy circuit having substantially the same structure as the logical value determination circuit.

13. A semiconductor integrated circuit having a current-sense type logic circuit comprising:

a logical value determination circuit configured to define a logical value and having a plurality of logic determination elements that define multiple electric paths extending in parallel between a logic node and a standard voltage source, each logic determination element having a control electrode configured to receive a logic input signal, and each electric path being controlled by an associated control electrode thereof based on the logic input signal applied to the control electrode;

a reference current generator configured to produce a reference current which is used to determine a logic; and

a current sense amplifier configured to amplify and output a difference between the reference current and an electric current flowing through the logical value determination circuit corresponding to the logical value.

14. The semiconductor integrated circuit according to claim 13, wherein the current sense amplifier comprises:

a first output node and a second output node;

a first load connected between a voltage source and the first output node;

a first driving transistor connected between the first output node and the logical value determination circuit, the gate of the first driving transistor being connected to the second output node;

a second load connected between the voltage source and the second output node; and

a second driving transistor connected between the second output node and the reference current generator, the gate of the second driving transistor being connected to the first output node.

15. The semiconductor integrated circuit according to claim 14, wherein the logic node is connected to the first output node of the current sense amplifier.

16. The semiconductor integrated circuit according to claim 15, wherein one or more logic determination elements are electrically inserted in series in each of the electric paths between the logic node and the standard voltage.

17. The semiconductor integrated circuit according to claim 16, wherein the reference current generator comprises one or more reference current generating elements connected in series, said one or more reference current generating elements defining an electric path with a cross-section smaller than the cross-section of a minimum-current electric path, through which the minimum current flows in the logical value determination circuit.

18. The semiconductor integrated circuit according to claim 17, wherein the reference current generating elements and the logical value determination elements are insulating-gate field effect transistors, and the channel width of the reference current generating elements is one half of the channel width of the logical value determination elements.

19. The semiconductor integrated circuit according to claim 14, wherein the current sense amplifier further comprise:

a voltage sense amplifier detecting a current difference between the currents output from the first and second output nodes and amplifying the current difference as a voltage difference; and

an inverter for enhancing and inverting the logical value output from the voltage sense amplifier.

20. The semiconductor integrated circuit according to claim 13, wherein the current sense amplifier is a latch-type current sense amplifier.

21. The semiconductor integrated circuit according to claim 13, wherein the reference current generator produces a reference current of between a level of a true value and a level of a false value defined by the logical value determination circuit.

22. The semiconductor integrated circuit according to claim 13, wherein the reference current generator produces a reference current which lies between an electric current of zero level and a minimum current that can flow through the electric paths according to the logical value defined by the logical value determination circuit.

23. A current-sense type logic circuit comprising:

a logical value determination circuit configured to define a logical value, and having a plurality of logic determination elements that define multiple electric paths extending in parallel between a logic node and a standard voltage source, each logic determination element having a control electrode configured to receive a logic input signal, and each electric path being controlled by the associated control electrode based on the logic input signal applied to the control electrode;

a reference current generator configured to produce a reference current which is used to determine a logic, and having one or more reference current generating elements, said one or more reference current generating elements being connected in series and defining an electric path with a cross-section smaller than the cross-section of a minimum-current electric path, through which the minimum current flows in the logical value determination circuit;

a current sense amplifier configured to detect and amplify a difference between the reference current and an electric current flowing through the logical value determination circuit corresponding to the logical value;

a first dummy circuit connected to the current sense amplifier in parallel to the logical value determination circuit, the first dummy circuit having substantially the same structure as the reference current generator; and

a second dummy circuit connected to the current sense amplifier in parallel to the reference current generator, the second dummy circuit having substantially the same structure as the logical value determination circuit.

24. A semiconductor integrated circuit having a current-sense type logic circuit comprising:

a logical value determination circuit configured to define a logical value, and having a plurality of logic determination elements that define multiple electric paths extending in parallel between a logic node and a standard voltage source, each logic determination element having a control electrode configured to receive a logic input signal, and each electric path being controlled by the associated control electrode based on the logic input signal applied to the control electrode;

a reference current generator configured to produce a reference current which is used to determine a logic, and having one or more reference current generating elements, said one or more reference current generating elements being connected in series and defining an electric path with a cross-section smaller than the cross-section of a minimum-current electric path, through which the minimum current flows in the logical value determination circuit;

a current sense amplifier configured to detect and amplify a difference between the reference current and an electric current flowing through the logical value determination circuit corresponding to the logical value;

a first dummy circuit connected to the current sense amplifier in parallel to the logical value determination circuit, the first dummy circuit having substantially the same structure as the reference current generator; and

a second dummy circuit connected to the current sense amplifier in parallel to the reference current generator, the second dummy circuit having substantially the same structure as the logical value determination circuit.