Circuit of sensing a fuse cell in a flash memory

• US 6,021,067 A
• Filed: 12/11/1998
• Issued: 02/01/2000
• Est. Priority Date: 12/23/1997
• Status: Expired due to Term

• Current Assignee: Hyundai Electronics Industries Co. Ltd. (SK Hynix Inc.)
• Original Assignee: Hyundai Electronics Industries Co. Ltd. (SK Hynix Inc.)
• Inventors: Ha, Chang Wan
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): Nguyen, Tuan T.
• Application Number:
  US09/210,172
• Time in Patent Office: 417 Days
• Field of Search: 365/185.21, 365/225.7, 365/185.33
• US Class Current: 365/185.21
• CPC Class Codes: G11C 16/20 Initialising; Data preset; Chip identification
• CPC Class Codes: G11C 7/067 Single-ended amplifiers

Abstract

This invention discloses a circuit of sensing a fuse cell used for repairing a failed memory cell, the circuit comprising a power-on reset circuit to generate reset pulses at the time of power-on of the flash memory, a reference circuit to latch an initial state according to output signal of the power-on reset circuit, a voltage divider circuit to output the voltage for sensing a fuse cell in said reference circuit according to output signal of the reference circuit, and a main memory cell data latch circuit to latch information on the fuse cell according to output signals of the power-on reset circuit and the reference circuit.

Claims

1. A circuit of sensing a fuse cell in a flash memory, comprising:

a power-on resist circuit to generate a reset pulse at the time of power-on of the flash memory;

a reference circuit to latch an initial state according to an output signal of said power-on reset circuit, said reference circuit comprising said fuse cell;

a voltage divider circuit to output the voltage for sensing said fuse cell in said reference circuit according to an output signal of said reference circuit; and

a main memory cell data latch circuit to latch information on said fuse cell according to said output signals of said power-on reset circuit and said reference circuit.

2. The circuit of claim 1, wherein said reference circuit comprises:

an initializing circuit to initialize said latch circuit according to said output signal of said power-on reset circuit; and

a delay circuit to delay an output or said latch circuit and to control said fuse cell and said voltage divider circuit.

3. The circuit of claim 2, wherein said sensing circuit comprises:

a pair of NMOS transistors connected between said latch circuit and said fuse cell in series and to which output of said power-on reset circuit and said voltage divider circuit are input.

4. The circuit of claim 2, wherein said latch circuit comprises a pair of inverters connected between said initializing circuit and said sensing circuit.

5. The circuit of claim 2, wherein said initializing circuit comprises;

a PMOS transistor which is connected between said latch circuit and a power terminal and to which an output of said power-on reset circuit is input; and

a NMOS transistor which is connected between said latch circuit and a grounded terminal and to which an output of said power-on reset circuit is input through an inverter.

6. A circuit of sensing a fuse cell in a flash memory, comprising:

a power-on resist circuit to generate a reset pulse at the time of power-on of the flash memory;

a reference circuit to latch an initial state according to an output signal of said power-on reset circuit, said reference circuit comprising said fuse cell, a sensing circuit to sense data on said fuse cell, a latch circuit to latch data of said fuse cell which are sensed by said sensing circuit, an initializing circuit to initialize said latch circuit according to said output signal of said power-on reset circuit and a delay circuit to delay an output of said latch circuit and to control said fuse cell and said voltage divider circuit;

a voltage divider circuit to output the voltage for sensing a fuse cell in said reference circuit according to an output signal of said reference circuit; and

a main memory cell data latch circuit to latch information on said fuse cell according to said output signals of said power-on reset circuit and said reference circuit.

7. The circuit of claim 6, wherein said sensing circuit comprises:

a pair of NMOS transistors connected between said latch circuit and said fuse cell in series and to which output of said power-on reset circuit and said voltage divider circuit are input.

8. The circuit of claim 6, wherein said latch circuit comprises a pair of inverters connected between said initializing circuit and said sensing circuit.

9. The circuit of claim 6, wherein said initializing circuit comprises:

a PMOS transistor which is connected between said latch circuit and a power terminal and to which output of said power-on reset circuit is input; and

an NMOS transistor which is connected between said latch circuit and a grounded terminal and to which output of said power-on reset circuit is input through an inverter.