Renesas Electronics Corporation

Toyota Jidosha Kabushiki Kaisha

Yoshihiro Nagai

Masami Hanyu

Masato Taki

Masahiko Kashimura

Masakazu Amanai

Kazushi Yamanaka

Norihiro Honda

A semiconductor memory device according to the present invention includes a first memory cell, a second memory cell, a dummy transistor, and a voltage control circuit. The first memory cell has a first transistor that is coupled to a first word line, a first source line, and a bit line. The second memory cell has a second transistor that is coupled to a second word line, a second source line, and the bit line. The dummy transistor has the same structure as the first transistor and is coupled to a dummy word line, a dummy source line, and a dummy bit line. When a predetermined voltage for writing data into the first memory cell is to be applied to the first word line, the voltage control circuit couples the dummy bit line to the second source line and applies the predetermined voltage to the first dummy word line.

Semiconductor memory device

Booster circuit comprising: first transistor that is connected to first node; capacitor that has one end connected to first node, and that is charged with voltage of first node when first transistor is activated; and control signal generating circuit that provides control terminal of first transistor with control signal being in accordance with first clock, wherein when first transistor is de-activated, capacitor boosts voltage of first node to first voltage by voltage being applied to or end of capacitor, voltage applied to or end being at least &#xbd; as great as first supply voltage, and control signal generating circuit sets voltage of control signal when first transistor is de-activated to be first voltage of first node, and sets voltage of control signal when first transistor is activated to be voltage, difference between voltage and first voltage being equal to or smaller than value of first supply voltage.

Booster circuit

A nonvolatile memory device includes a memory cell that stores data by presence or absence of electrons accumulated in a floating gate, a read reference current generator that generates a read reference current for reading data from the memory cell based on a constant current from a constant current generator included therein, and a read voltage generator that generates a read voltage to be applied to a control gate of the memory cell during data reading. The read reference current generator generates a monitor voltage that varies according to variation of the read reference current and a threshold voltage of the memory cell. The read voltage generator generates the read voltage based on the monitor voltage.

Nonvolatile semiconductor memory device

Growing community of inventors

Kawasaki, Japan

Yoshihiro Nagai