US 6,982,910 B2 | ||
Reverse voltage generation circuit | ||
Shinya Yamase, Ota (Japan) | ||
Assigned to Sanyo Electric Co., Ltd., Osaka (Japan) | ||
Filed on Feb. 16, 2005, as Appl. No. 11/58,429. | ||
Claims priority of application No. 2004-042462 (JP), filed on Feb. 19, 2004. | ||
Prior Publication US 2005/0185469 A1, Aug. 25, 2005 | ||
Int. Cl. G11C 7/00 (2006.01) |
U.S. Cl. 365—189.09 | 5 Claims |
1. A reverse voltage generation circuit comprising:
a semiconductor substrate of a first general conductivity type;
a first well of a second general conductivity type, a second well of the second general conductivity type and a third well
of the second general conductivity type that are formed in the semiconductor substrate;
a first charge transfer MOS transistor of a channel type of the first general conductivity type formed in a surface of the
first well, comprising a first diffused region of the first general conductivity type that is connected to the first well
and a ground providing a ground voltage, and further comprising a second diffused region of the first general conductivity
type;
a second charge transfer MOS transistor of a channel type of the second general conductivity type formed in a surface of the
semiconductor substrate and comprising a first diffused region of the second general conductivity type connected to the second
diffused region of the first charge transfer MOS transistor;
a first driver MOS transistor of the channel type of the first general conductivity type formed in a surface of the second
well, comprising a first diffused region of the first general conductivity type that is connected to the second well and a
power supply providing a power supply voltage, and further comprising a second diffused region of the first general conductivity
type;
a second driver MOS transistor of the channel type of the first general conductivity type formed in a surface of the third
well, comprising a first diffused region that is connected to the third well and the second diffused region of the first driver
MOS transistor, and further comprising a second diffused region connected to the ground;
a capacitor comprising a terminal connected to the second diffused region of the first charge transfer MOS transistor and
the first diffused region of the second charge transfer MOS transistor and another terminal connected to the second diffused
region of the first driver MOS transistor and the first diffused region of the second driver MOS transistor; and
a control circuit that controls turning on and off of the first charge transfer MOS transistor, the second charge transfer
MOS transistor, the first driver MOS transistor and the second driver MOS transistor,
wherein a second diffused region of the second general conductivity type of the second charge transfer MOS transistor is configured
to output a reverse power supply voltage that is opposite in polarity to the power supply voltage.
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