Amplifiers – With semiconductor amplifying device – Including differential amplifier
Reexamination Certificate
2000-06-15
2002-02-26
Mottola, Steven J. (Department: 2817)
Amplifiers
With semiconductor amplifying device
Including differential amplifier
C330S264000
Reexamination Certificate
active
06351187
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention related to operational amplifiers, and more particularly to an improved amplifier structure which consumes no electric current and provides a stable output when not working.
Following rapid development of integrated circuit technology, advanced ICs, such as micro-controllers, digital-to-analog converters, memory devices, and etc., are made having a minimized dimension with sophisticated operation capability. Operational amplifiers are used in a variety of IC chips.
FIG. 1
illustrates a conventional operational amplifier. This amplifier structure is composed of CMOS (complementary metal-oxide semiconductor) comprising a differential amplifier
10
, a reverse output buffer
20
, a non-inverting terminal IP, an inverting terminal IN, a bias voltage input terminal AVB, and an output terminal OI. The differential amplifier
10
is composed of semiconductor switches M
1
~M
5
, and is connected to the non-inverting terminal IP and the inverting terminal IN. The reverse output buffer
20
is comprised of two semiconductor switches, namely, the reverse switch M
6
and the forward switch M
7
connected between a reference voltage and a grounding terminal GND. The output terminal O
1
is connected between the semiconductor switches M
6
and M
7
of the reverse output buffer
20
. An input bias voltage signal is provided through the bias voltage input buffer
20
to electrically connect the forward switch M
7
, so as to achieve proportional output. This structure of this operational amplifier is commonly used in mobile electronic apparatus such as mobile telephones, notebook computers, and personal digital assistant. However, this amplifier structure is not satisfactory because it consumes to much electric current when not working.
SUMMARY OF THE INVENTION
It is the main object of the present invention to provide an operational amplifier, which consumes no power AND provides a stable output signal through its output terminal when it is not working. The reverse output buffer according to the present invention comprises a second reverse switch and a second forward switch. The second reverse switch is connected is connected in series between the first reverse switch and the reference voltage. The second forward switch is connected is connected between the output terminal and the grounding terminal GND. A bias voltage provided from a second bias voltage input terminal of the operational amplifier electrically connects the second reverse switch and the second forward switch. When the second bias voltage input terminal is at low potential and the first bias voltage input terminal is at high potential, the second reverse is on, and the second forward switch is off, thereby causing the operational amplifier to function normally. When the s second bias voltage input terminal is at high potential and first bias voltage input terminal is at low potential, the second reverse switch is off, and the second forward switch is on, thereby causing the operation amplifier to consume no electricity, and the output terminal to provide a stable low voltage output.
REFERENCES:
patent: 5049833 (1991-09-01), Miller
patent: 5818295 (1998-10-01), Chimura et al.
patent: 6018267 (2000-01-01), Tran et al.
patent: 6057734 (2000-05-01), Xu
CAsey, Esq. Donald C.
Micon Design Technology Co. LTD
Mottola Steven J.
LandOfFree
Structure of operational amplifier does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Structure of operational amplifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structure of operational amplifier will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2960365