Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Masanori Shirahama

Toshiaki Kawasaki

Yasuhiro Agata

Ryuji Nishihara

Masashi Agata

Yasue Yamamoto

Shinichi Sumi

Hirohito Kikukawa

Naoki Kuroda

Kazunari Takahashi

Toshikazu Suzuki

Yutaka Terada

Yoshinobu Yamagami

Tsutomu Fujita

Katsuya Arai

Mitsuaki Hayashi

Marefusa Kurumada

Hiroyuki Sadakata

Kenji Misumi

Toshihiro Kougami

Kohtaro Hayashi

Tomoyuki Aihara

A semiconductor device includes an electric fuse circuit and a program protective circuit. The electric fuse circuit includes a fuse element and a transistor connected together in series and placed between a program power supply and a grounding, and controlling sections. The program protective circuit is placed in parallel with the electric fuse circuit and between the program power supply and the grounding. When a surge voltage is applied between the program power supply and the grounding, the foregoing structure allows a part of a surge electric current can flow through the program protective circuit.

Semiconductor device

In a nonvolatile semiconductor memory device storing data by accumulating charges in a floating gate, memory units, each of which includes a first MOS transistor as a read device, a bit cell composed of a first capacitor as a capacitance coupling device and a second capacitor as an erase device, and a decode device including a second MOS transistor and a third MOS transistor, are arranged in array. This attains nonvolatile memory capable of bit by bit selective erase arranged in array to thus reduce the core area remarkably.

Nonvolatile semiconductor memory device

An electronic equipment system includes a semiconductor integrated circuit having a nonvolatile memory storing information on a characteristic of the semiconductor integrated circuit; and a controller configured to control the semiconductor integrated circuit. The controller has a function of adjusting an access parameter to the semiconductor integrated circuit based on the information stored in the nonvolatile memory.

Electronic equipment system and semiconductor integrated circuit controller

A semiconductor memory device includes a memory cell provided at an intersection of a word line and a bit line, a precharge circuit connected to the bit line, a column select circuit controlled in accordance with a write control signal, and a clamp circuit provided as a write circuit. The clamp circuit includes a transistor configured to control the potential of a selected bit line to a first potential (e.g., 0 V), and a variable capacitor configured to control the potential of the selected bit line to a second potential (e.g., a negative potential) which is lower than the first potential. The capacitance of the variable capacitor decreases when a power supply voltage is increased, whereby the amount of a decrease from the first potential to the second potential is reduced.

Semiconductor memory device

A system LSI includes an input/output section and a logic circuit section. The input/output section includes an I/O power source cell having a supply voltage higher than a power source for the logic circuit section and a plurality of I/O cells in each of which an I/O power source line is provided for supplying source power from the I/O power source cell. The logic circuit section includes an I/O power consuming circuit which uses the I/O power source cell as a power source. The I/O power consuming circuit is connected to a line leading from an I/O power source line in at least one of the plurality of I/O cells.

System LSI

A first transistor is connected in series with one end of a fuse element. A second transistor is connected in series with the other end of the fuse element. A current flows through the fuse element when both the first and second transistors are turned on.

Electric fuse circuit available as one time programmable memory

A gate of a MOS transistor connected to a fuse device in series is controlled by an AND circuit connected to the same power source as the fuse device is connected, thereby pulling down one input of the AND circuit to a ground. Thus, misprogramming of the fuse device when an LSI power source is turned ON/OFF can be prevented.

Electrical fuse circuit

A nonvolatile semiconductor memory device for storing data by accumulating charge in a floating gate includes a plurality of MOS transistors sharing the floating gate. In the device, a PMOS is used for coupling during writing and an n-type depletion MOS (DMOS) is used for coupling during erasure. Coupling of channel inversion capacitance by the PMOS is used for writing and coupling of depletion capacitance by the n-type DMOS is used for erasure, thereby increasing the erase speed without increase of area, as compared to a conventional three-transistor nonvolatile memory element.

A circuit includes a plurality of stages each including a MOS transistor and a capacitor of which one end is connected to one of a drain and a source of the MOS transistor. The plurality of stages are connected with each other by cascade connection of the MOS transistors. A gate of the MOS transistor is connected electrically to one of the drain and the source thereof in each stage, and a substrate for at least one pair of adjacent MOS transistors are connected electrically to one of the drain and the source of one of the pair. The back bias effect is suppressed, and the layout area is reduced. Further, a plurality of booster capacitors connected in series are provided in succeeding stages, thereby suppressing degradation of breakdown voltage of each capacitor.

Charge-pump circuit

A memory cell is constructed by connecting in series a variable-resistance element having a resistance which is varied by application of a positive voltage to one terminal (first node) thereof using a potential at the other terminal thereof as a reference and a diode which allows a current to flow therethrough by application of a positive voltage to the other terminal thereof using a potential at one terminal (second node) thereof as a reference. The first node is connected to the corresponding column select line and the second node is connected to the corresponding row select line. Then, to a non-selected row select line, a potential higher than when the row select line is selected is applied by using a row control circuit. By using column-select-line driver circuits, predetermined potentials corresponding to a non-selection period, a data write period, a reset period, and a data read period are applied to the column select line.

In a semiconductor memory device including resistance change memory devices, when a resistance change memory device is in standby mode, the two terminals of the resistance change memory device, i.e., a bit line and a source line, are set at a precharge potential Vp, respectively. At the time of a set operation, the bit line is set to a set voltage Vd, which is higher than the precharge potential Vp, while the source line is grounded. At the time of a reset operation, bit line is grounded, while the source line is set to the set voltage Vd. At the time of a data-read operation, the source line is grounded by a read bias generation circuit, while the potential of the bit line is kept at the precharge potential Vp.

Semiconductor memory device and semiconductor integrated circuit system

Electrical fuse blocks () of a plurality of stages are provided each of which includes a plurality of electrical fuse cores (). The electrical fuse block () includes a program shift register block () made up of shift registers () which are disposed for the respective electrical fuse cores (), sequentially transmit program enable signal FPGI, and output the program enable signal FPGI to the NMOS transistors () of the electrical fuse cores (). When performing programming according to programming decision signal PBn, the program shift register block () transmits the program enable signal FPGI. When not performing programming, the program shift register block () skips the program enable signal FPGI.

Semiconductor storage device including electrical fuse module

An electrical fuse circuit of the present invention includes a plurality of electrical fuse cores () each of which has an electrical fuse element () and a switch transistor () connected in series with each other, and shift registers () connected to the plurality of electrical fuse cores () to program the electrical fuse elements (). Program enable signals (Si) are sequentially generated and transferred by the shift registers (), the switch transistors () are sequentially brought into conduct according to the program enable signals (Si) and the information of program data (Di), and the electrical fuse elements () are blown one by one.

Growing community of inventors

Shiga, Japan

Masanori Shirahama