Sanyo Electric Co., Ltd.

Kenya Uesugi

Michiru Senda

Keiichi Sano

Sadao Yoshikawa

Masayuki Koga

Koji Marumo

Kuni Yamamura

When a switching TFT is switched on, a data voltage on a data line is stored in a storage capacitor as a gate voltage of a driver TFT. In this state, a voltage on a pulse drive line is caused to fall. AMOS type capacity element having a second electrode connected to a reference voltage is connected to a gate of the driver TFT. The MOS type capacity element is in an ON state before a fall of the pulse drive line and becomes an OFF state during the fall, and a capacitance changes at the switching of ON state to the OFF state. Therefore, the slope of fall of the gate voltage changes, and the gate voltage after the fall on the pulse drive line can be corrected corresponding to the variation in the threshold values among driver TFTs.

Pixel circuit and display device

A write control circuit that generates a control signal to initiate a write operation for a semiconductor memory device, such as an EEPROM, compensates for fluctuations in the supply voltage. The write control circuit includes a control potential generator that produces a first control potential which is kept higher than the ground potential and a second control potential which is kept lower than the supply potential. A first transistor is connected to the supply potential and receives a write potential at its gate. A second transistor is connected between the first transistor and ground and receives the first control potential at its gate. A third transistor is connected to the supply potential and receives the second control potential at its gate. A fourth transistor is connected between the third transistor and ground and receives a potential from a first node between the first and second transistors at its gate. The control signal is generated at a second node between the third and fourth transistors. The control signal is activated when the write potential reaches a certain value.

Write control circuit for semiconductor memory device

Growing community of inventors

Ohgaki, Japan

Kenya Uesugi