Electronic digital logic circuitry – Interface – Current driving
Patent
1996-04-22
1998-04-28
Westin, Edward P.
Electronic digital logic circuitry
Interface
Current driving
326 34, H03K 190175
Patent
active
057449821
ABSTRACT:
A CMOS inverter has two p-channel FETs connected in series between V.sub.DD and the inverter output node, an upper FET connected to V.sub.DD and a lower FET connected to the output node. The gate of a upper FET and the gate of the inverter n-channel FET are connected to the circuit input through a series FET that protects the gate oxide of these FETs by turning off if a high voltage appears at the circuit input. The circuit is useful as a buffer that receives binary voltages that may be higher than the binary voltages of the circuits of the same chip. The gate of the upper p-channel FET is connected to the input and turns off fully to block a leakage current that would otherwise flow when the n-channel FET is turned on but the lower p-channel FET is left partly conducting by the voltage drop across the series FET. The gate oxide of the upper FET is protected because the partly conducting lower p-channel FET is turned off sufficiently to impede the charging current of the capacitor formed in part by the gate oxide.
REFERENCES:
patent: 4825106 (1989-04-01), Tipon et al.
patent: 5144165 (1992-09-01), Dhong et al.
patent: 5270589 (1993-12-01), Sawada et al.
patent: 5300835 (1994-04-01), Assar et al.
patent: 5304872 (1994-04-01), Avraham et al.
patent: 5319259 (1994-06-01), Merrill
patent: 5410267 (1995-04-01), Haycock et al.
patent: 5422592 (1995-06-01), Asahina
patent: 5426383 (1995-06-01), Kumar
patent: 5495185 (1996-02-01), Goto
patent: 5495187 (1996-02-01), Martin
patent: 5541534 (1996-07-01), Cao et al.
Ackerman Stephen B.
Robertson William S.
Roseen Richard
Saile George O.
Taiwan Semiconductor Manufacturing Company , Ltd.
LandOfFree
Input buffer circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Input buffer circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Input buffer circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1535859