Active solid-state devices (e.g. – transistors – solid-state diode – Field effect device – Having insulated electrode
Reexamination Certificate
1996-11-25
2003-01-14
Cao, Phat X. (Department: 2814)
Active solid-state devices (e.g., transistors, solid-state diode
Field effect device
Having insulated electrode
C257S344000
Reexamination Certificate
active
06507070
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates, in general, to semiconductor devices, and more particularly to semiconductor devices having bi-directional current blocking capability.
Many portable electronic devices use a lithium-ion battery as a power source. Lithium-ion batteries require a monitoring circuit to control the flow of current when the lithium-ion battery is used as a power source and when the lithium-ion battery is being charged. When in operation, the voltage potential across the battery must be monitored to ensure that the voltage potential of the lithium battery does not drop too low. If the lithium-ion battery is operated when the voltage potential of the battery is too low, the future performance of the lithium-ion battery can be degraded. Furthermore, lithium-ion batteries are very sensitive to the amount of current that passes through the battery when it is being charged.
Therefore, lithium batteries require a monitoring circuit that is both bilateral, allows current to flow in both directions, and that can withstand significant voltages while current is blocked in either direction. One way of providing this functionality is to place two n- or p-channel vertical field effect transistors in a back-to-back configuration so that they share a common source/drain.
Using two transistors in a back-to-back configuration has several disadvantages. Firstly, the channel region of two devices results in a higher on resistance in the current path. Secondly, the formation of two devices in a back-to-back configuration requires significant surface area, which results in a high die cost and an higher overall manufacturing cost.
Accordingly, a need exists to provide a semiconductor device that can operate bi-directionally and provide the necessary voltage protection when a lithium battery is in operation and when it is being charged. It would be advantageous if the semiconductor device can be formed using less surface area than traditional devices and using fewer processing steps.
REFERENCES:
patent: 4079504 (1978-03-01), Kosa
patent: 4716446 (1987-12-01), Esser et al.
patent: 4717940 (1988-01-01), Shinohe et al.
patent: 4799098 (1989-01-01), Ikeda et al.
patent: 4887135 (1989-12-01), Cheney et al.
patent: 4914043 (1990-04-01), Nishizawa et al.
patent: 4942444 (1990-07-01), Ablassmeier
patent: 5191401 (1993-03-01), Shirai et al.
patent: 5256893 (1993-10-01), Yasuoka
patent: 5393999 (1995-02-01), Malhi
patent: 5420451 (1995-05-01), Williams et al.
patent: 5430316 (1995-07-01), Contiero et al.
patent: 5528058 (1996-06-01), Pike et al.
patent: 5648673 (1997-07-01), Yasuda
patent: 0356039 (1990-02-01), None
patent: 0520831 (1992-12-01), None
patent: 51-85381 (1976-07-01), None
patent: 60-251669 (1985-12-01), None
patent: 06204463 (1994-07-01), None
Williams et al., Siliconix, Inc., Proceedings of 1995 International Symposium on Power Semiconductor Devices & ICs. Yokohama, “The Bidirectional Power NMOS- A New Concept in Battery Disconnect Switching”, pp. 480-485.
Mitter Chang Su
Robb Stephen P.
Shen Zheng
Cao Phat X.
Semiconductor Components Industries LLC
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