EP0472128A2
Expired / Lapsed
EP
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Constant-voltage generation circuit
Assignee: Oki Electric Industry Co Ltd
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Filing: 1991-08-16
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Granted: —
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Expires: 2011-08-16
Abstract
Abstract The constant-voltage generation circuit according to the present invention incorporates a reference voltage generation circuit employing a first and a second transistors which output a first and a second reference voltages based on a bandgap voltage and controlling a current flow from a power source in response to a standard output voltage, a first level shift circuit generating a third reference voltage based on the first reference voltage, a second level shift circuit generating a fourth reference voltage based on the second reference voltage, and a standard voltage generation circuit which inputs the third and the fourth reference voltages respectively to the first and the second input terminals and amplifies the difference voltage between the third and the fourth reference voltages so as to output the standard output voltage. <IMAGE>
Inventors
- 👤 Kazushige Yamamoto
- 👤 Hiroyuki Tokutomi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 04:10
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/26; G05F3/267
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
107 words
A constant-voltage generation circuit for preserving an output voltage at a constant voltage level comprising: a) a reference voltage means coupled to a power source for outputting a first and a second reference voltages in response to a standard output voltage; b) a first level shift means for outputting a third reference voltage in response to the first reference voltage; c) a second level shift means for outputting a fourth reference voltage in response to the second reference voltage; and d) a standard voltage generation means for outputting the standard output voltage by amplifying a differential voltage between the third reference voltage and the fourth reference voltage.
Claim 2
Dependent Claim
157 words
The constant-voltage generation circuit in accordance with claim 1, wherein the reference voltage means comprises a first and a second bipolar transistors; collectors of which being connected to the power source; bases of which being commonly connected each other and the standard output voltage being provided thereto; and a first, a second and a third resistor means; an emitter of the first bipolar transistor being connected to one end of the first resistor means; the other end of the first resistor means being connected to one end of the second resistor means; the other end of the second resistor means being connected to one end of the third resistor means; the other end of the third resistor means being connected to an emitter of the second bipolar transistor, whereby the first reference voltage appears at one end of the second resistor means, and the second reference voltage appears at the other end of the third resistor means.
Claim 3
Dependent Claim
65 words
The constant-voltage generation circuit in accordance with claim 1, wherein the first level shift means comprises a first constant-current source and a first level shift driving means connected each other in series, whereby the third reference voltage is generated between the first level shift driving means and the first constant-current source when the first reference voltage is inputted to the first level shift driving means.
Claim 4
Dependent Claim
26 words
The constant-voltage generation circuit in accordance with claim 3, wherein the first constant-current source and the first level shift driving means are constituted by PMOS transistors.
Claim 5
Dependent Claim
28 words
The constant-voltage generation circuit in accordance with claim 4, wherein the PMOS transistor of the first constant-current source is controlled at its base by an external bias voltage.
Claim 6
Dependent Claim
65 words
The constant-voltage generation circuit in accordance with claim 1, wherein the second level shift means comprises a second constant-current source and a second level shift driving means connected each other in series, whereby the fourth reference voltage is generated between the second level shift driving means and the second constant-current source when the second reference voltage is inputted to the second level shift driving means.
Claim 7
Dependent Claim
26 words
The constant-voltage generation circuit in accordance with claim 6, wherein the second constant-current source and the second level shift driving means are constituted by PMOS transistors.
Claim 8
Dependent Claim
28 words
The constant-voltage generation circuit in accordance with claim 7, wherein the PMOS transistor of the second constant-current source is controlled at its base by an external bias voltage.
Claim 9
Dependent Claim
21 words
The constant-voltage generation circuit in accordance with claim 1, wherein the standard voltage generation means is constituted by an operational amplifier.
Claim 10
Dependent Claim
27 words
The constant-voltage generation circuit in accordance with claim 5, wherein the PMOS transistor has the same input-output characteristics as those of the PMOS transistor in claim 8.
References Cited (Backward Citations)
No citation records indexed.
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