# US 5,345,122 A · Cascade sense amplifier for reading out data stored in semiconductor memory device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,345,122 A
- Document ID: US5345122A
- Status: Granted
- Kind: A
- Application number: 08/051,305
- Filed: 1993-04-22
- Granted: 1994-09-06
- Earliest claimed: 1992-04-23
- Assignees: Kabushiki Kaisha Toshiba
- Inventors: Hiroshi Takamoto; Takenori Nakamura; Kenichi Nakamura
- Web page: https://patentgrep.com/patent/US5345122A

## CPC

- G11C 7/062: {Differential amplifiers of non-latching type, e.g. comparators, long-tailed pairs}
- H03K 5/2418: {with at least one differential stage}
- H03K 5/2427: {using clock signals}
- G11C: STATIC STORES (semiconductor memory devices H10B)
- H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M)

## Abstract

A cascade sense amplifier includes section separated sense amplifiers, a cascade wiring and a main sense amplifier. The main sense amplifier has a capacitance regulation element provided at a base potential of input transistors constituting a data input end. The element is comprised of a metal oxide semiconductor (MOS) transistor for forming a capacitance corresponding to a potential V.sub.SS mainly forming a capacitance by the cascade wiring. A size of the element is determined in the manner that the base potential drop time of the transistors is equal to a potential drop time of the cascade wiring when a power source voltage V.sub.CC drops. Even though the power source voltage V.sub.CC drops, the transistors have no cut-off condition so as to prevent the read-out time from delaying. Especially, if the element is comprised of a MOS transistor, it is possible to use an extremely thin gate insulation layer as a dielectric, thereby suppressing an increase of a chip size.

## Claims

### Claim 1

A cascade sense amplifier, comprising
a plurality of section separated sense amplifiers, each of which opposes to each of section cell array, and which senses data stored in corresponding section cell array;
a cascade wiring portion for commonly connecting a plurality of output ends of said plurality of section separated sense amplifier;
a main sense amplifier having a bipolar transistor as a data input end and for amplifying each output from each of said section separated sense amplifiers through said cascade wiring portion; and
a capacitance regulation element for regulating a capacitance of a base potential of said bipolar transistor constituting the data input end of said main sense amplifier.

### Claim 2 (depends on 1)

The cascade sense amplifier according to claim 1 wherein said capacitance regulation element is comprised of an element for setting a capacitance equal to a capacitance of said cascade wiring portion.

### Claim 3 (depends on 2)

The cascade sense amplifier according to claim 2 wherein said capacitance regulation element is comprised of an metal oxide semiconductor (MOS) transistor.

### Claim 4 (depends on 2)

The cascade sense amplifier according to claim 2 wherein a capacitance value of said capacitance regulation element is set in a manner such that a potential drop time of a base of said bipolar transistor in said main sense amplifier is equal to a potential drop time of said cascade wiring portion when a power supply voltage of said sense amplifier fluctuates.

### Claim 5 (depends on 1)

The cascade sense amplifier according to claim 1 wherein said capacitance regulation element is comprised of an N-channel MOS transistor.

### Claim 6 (depends on 5)

The cascade sense amplifier according to claim 5 wherein a capacitance value of said capacitance regulation element is set in the manner that a potential drop time of a base of said bipolar transistor in said main sense amplifier is equal to a potential drop time of said cascade wiring portion when a power supply voltage of said sense amplifier fluctuates.

### Claim 7 (depends on 1)

The cascade sense amplifier according to claim 1 wherein a capacitance value of said capacitance regulation element is set in the manner that a potential drop time of a base of said bipolar transistor in said main sense amplifier is equal to a potential drop time of said cascade wiring portion when a power supply voltage of said sense amplifier fluctuates.