US4868417A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Complementary voltage comparator
Assignee: Motorola Solutions Inc
•
Filing: 1988-08-23
•
Granted: 1989-09-19
•
Expires: 2008-08-23
Abstract
Abstract A complementary voltage comparator is described wherein a CMOS operational amplifier having an input stage comprising N-channel field effect transistors is coupled with a CMOS operational amplifier having an input stage comprising P-channel field effect transistors. The outputs of the operational amplifiers are converted to currents and combined to indicate the relative magnitudes of the voltages being compared. This configuration allows the range of input voltages to vary over the full range of supply voltages and negates the need for offset correction.
Inventors
- 👤 Jaswinder S. Jandu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:38
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/22; H03K5/24; H03K5/2472; H03K5/2481
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
220 words
A comparator circuit having an output identifying which of first and second input voltages has a greater magnitude, said comparator circuit comprising: first amplifier means having a different input stage comprising transistor of a first conductivity type with inverting and noninverting inputs adapted for receiving said first and second input voltages, respectively, and providing a first signal exhibiting an error voltage therebetween, second amplifier means having a differential input stage comprising transistors of a second conductivity type with inverting and noninverting inputs adapted for receiving said first and second input voltages, respectively, and providing a second signal exhibiting an error voltage therebetween; first switching means coupled to said first amplifier means for receiving said first signal and coupled to an output terminal for providing a first current to said output terminal when the magnitude of said first input voltage is greater than the magnitude of said second input voltage; second switching means coupled to said second amplifier means for receiving said second signal and coupled to said output terminal for providing a second current to said output terminal when the magnitude of said first input voltage is greater than the magnitude of said second input voltage; and means for providing a resistance coupled to said output terminal for providing an output voltage in response to said first and second currents.
Claim 2
Dependent Claim
220 words
A comparator circuit having an output identifying which of first and second input voltages has a greater magnitude, said comparator circuit comprising: first amplifier means having a different input stage comprising transistor of a first conductivity type with inverting and noninverting inputs adapted for receiving said first and second input voltages, respectively, and providing a first signal exhibiting an error voltage therebetween, second amplifier means having a differential input stage comprising transistors of a second conductivity type with inverting and noninverting inputs adapted for receiving said first and second input voltages, respectively, and providing a second signal exhibiting an error voltage therebetween; first switching means coupled to said first amplifier means for receiving said first signal and coupled to an output terminal for providing a first current to said output terminal when the magnitude of said first input voltage is greater than the magnitude of said second input voltage; second switching means coupled to said second amplifier means for receiving said second signal and coupled to said output terminal for providing a second current to said output terminal when the magnitude of said first input voltage is greater than the magnitude of said second input voltage; and means for providing a resistance coupled to said output terminal for providing an output voltage in response to said first and second currents.
Claim 3
Dependent Claim
23 words
A comparator circuit according to claim 1 wherein said first and second amplifier means further comprise first and second CMOS operational amplifiers, respectively.
Claim 4
Dependent Claim
20 words
A comparator circuit according to claim 1 wherein said first and second switching means further comprise P-channel field effect transistors.
Claim 5
Dependent Claim
20 words
A comparator circuit according to claim 1 wherein said means for providing a resistance further comprises a field effect transistor.
Claim 6
Dependent Claim
23 words
A comparator circuit according to claim 2 wherein said first CMOS operation amplifier has a differential input stage comprising N-channel field effect transistors.
Claim 7
Dependent Claim
23 words
A comparator circuit according to claim 2 wherein said second CMOS operational amplifier has a differential input stage comprising P-channel field effect transistors.
Claim 8
Dependent Claim
160 words
A complementary voltage comparator circuit manufactured in monolithically integrated form for comparing first and second input voltages, comprising: a first amplifier having a differential input stage comprising transistors of a first conductivity type and having an inverting input coupled for receiving the first input voltage and a noninverting input coupled for receiving the second input voltage, said first operational amplifier providing a first current when the first input voltage is greater than the second input voltage; a second amplifier having a differential input stage comprising transistors of a second conductivity type and having an inverting input coupled for receiving the first input voltage and a noninverting input coupled for receiving the second input voltage, said second operational amplifier providing a second current when the first input voltage is greater than the second input voltage; and resistive means coupled to said first and second operational amplifiers for providing an output voltage when either of the first or second currents are present.
Claim 9
Dependent Claim
160 words
A complementary voltage comparator circuit manufactured in monolithically integrated form for comparing first and second input voltages, comprising: a first amplifier having a differential input stage comprising transistors of a first conductivity type and having an inverting input coupled for receiving the first input voltage and a noninverting input coupled for receiving the second input voltage, said first operational amplifier providing a first current when the first input voltage is greater than the second input voltage; a second amplifier having a differential input stage comprising transistors of a second conductivity type and having an inverting input coupled for receiving the first input voltage and a noninverting input coupled for receiving the second input voltage, said second operational amplifier providing a second current when the first input voltage is greater than the second input voltage; and resistive means coupled to said first and second operational amplifiers for providing an output voltage when either of the first or second currents are present.
Claim 10
Dependent Claim
19 words
A complementary voltage comparator circuit according to claim 7 wherein said resistive means further comprises a field effect transistor.
Claim 11
Dependent Claim
208 words
A comparator circuit manufactured in monolithically integrated form, said comparator circuit comprising: a first supply voltage terminal for receiving a first supply voltage; a second supply voltage terminal for receiving a second supply voltage; a first input terminal for receiving a first input signal; a second input terminal for receiving a second input signal; an output terminal; a first comparator having an input stage comprising N-channel field effect transistors, said first comparator having an inverting input coupled to said first input terminal, a noninverting input coupled to said second input terminal, and having a driver node; a second comparator having an input stage comprising P-channel field effect transistors, said second comparator having an inverting input coupled to said first input terminal, a noninverting input coupled to said second input terminal, and having a driver node; a first transistor coupled between said first supply voltage terminal and said output terminal, and having a control terminal coupled to the driver node of said first comparator; a second transistor coupled between said first supply voltage terminal and said output terminal, and having a control terminal coupled to the driver node of said second comparator; and means for providing a resistance coupled between said output terminal and said second supply voltage terminal.
Claim 12
Dependent Claim
208 words
A comparator circuit manufactured in monolithically integrated form, said comparator circuit comprising: a first supply voltage terminal for receiving a first supply voltage; a second supply voltage terminal for receiving a second supply voltage; a first input terminal for receiving a first input signal; a second input terminal for receiving a second input signal; an output terminal; a first comparator having an input stage comprising N-channel field effect transistors, said first comparator having an inverting input coupled to said first input terminal, a noninverting input coupled to said second input terminal, and having a driver node; a second comparator having an input stage comprising P-channel field effect transistors, said second comparator having an inverting input coupled to said first input terminal, a noninverting input coupled to said second input terminal, and having a driver node; a first transistor coupled between said first supply voltage terminal and said output terminal, and having a control terminal coupled to the driver node of said first comparator; a second transistor coupled between said first supply voltage terminal and said output terminal, and having a control terminal coupled to the driver node of said second comparator; and means for providing a resistance coupled between said output terminal and said second supply voltage terminal.
Claim 13
Dependent Claim
42 words
A comparator circuit according to claim 9 wherein said means for providing a resistance further comprises an N-channel field effect transistor having a gate and a drain coupled to said output terminal, and a source coupled to said second supply voltage terminal.
Claim 14
Dependent Claim
18 words
A comparator circuit according to claim 9 wherein said first and second transistors are P-channel field effect transistors.
Claim 15
Dependent Claim
33 words
A comparator circuit according to claim 9 further comprising a buffer means having an input coupled to said output terminal and having a driver node for waveshaping the signal at said output terminal.
Claim 16
Dependent Claim
16 words
A comparator circuit according to claim 12 wherein said buffer means further comprises a Schmitt trigger.
Claim 17
Independent Claim
200 words
A method of comparing first and second input voltages having magnitudes that may vary over a range defined by the magnitudes of first and second supply voltages comprising the steps of; comparing said first and second input voltages wherein said first and second input voltages may vary over a range defined by the magnitude of said first supply voltage to a magnitude that is at least two threshold voltages greater than the magnitude of said second supply voltage, and driving a first switching means for providing a first output current when said first input voltage is greater than said second input voltage; comparing said first and second input voltages wherein said first and second input voltages may vary over a range defined by the magnitude of said second supply voltage to a magnitude that is at least two threshold voltages less than the magnitude of said first supply voltage, and driving a second switching means for providing a second output current when said first voltage is greater than said second voltage; and providing a digital output voltage based on sum of said first and second output currents thereby indicating the difference in magnitudes of said first and second input voltages.
Claim 18
Independent Claim
200 words
A method of comparing first and second input voltages having magnitudes that may vary over a range defined by the magnitudes of first and second supply voltages comprising the steps of; comparing said first and second input voltages wherein said first and second input voltages may vary over a range defined by the magnitude of said first supply voltage to a magnitude that is at least two threshold voltages greater than the magnitude of said second supply voltage, and driving a first switching means for providing a first output current when said first input voltage is greater than said second input voltage; comparing said first and second input voltages wherein said first and second input voltages may vary over a range defined by the magnitude of said second supply voltage to a magnitude that is at least two threshold voltages less than the magnitude of said first supply voltage, and driving a second switching means for providing a second output current when said first voltage is greater than said second voltage; and providing a digital output voltage based on sum of said first and second output currents thereby indicating the difference in magnitudes of said first and second input voltages.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |