Stackable voltage comparator circuit for a multiple voltage window detector

Claim 2

A voltage comparator network for comparing an input voltage with voltage windows, the comparator network comprising: a first comparator circuit comparing an input voltage with a first threshold voltage, said first comparator circuit including a first differential input pair of transistors for receiving and comparing the input voltage with the first threshold voltage, the first differential input pair of transistors having one transistor with a first and a second collector, the second collector being coupled to an output line; and a second comparator circuit comparing the input voltage with a second threshold voltage, the second comparator circuit including a second differential input pair of transistors for comparing the input voltage with the second threshold voltage, said second comparator circuit having an input coupled to the output line of the first comparator circuit for receiving current when the input voltage is less than the first threshold voltage, said second comparator circuit further including an output for providing an output indicative or whether the input voltage is within a voltage window bounded by the first and second threshold voltages.

Claim 3

The voltage comparator network as defined in claim 1 wherein said first and second comparator circuits each receive sourced current supplied to the corresponding differential input pair of transistors.

Claim 4

The voltage comparator network as defined in claim 1 wherein said second comparator circuit further comprises a differential to single ended converter coupled to the second differential input pair of transistors.

Claim 5

The voltage comparator network as defined in claim 3 wherein said differential to single ended converter comprises a pair of base-coupled transistors.

Claim 6

The voltage comparator network as defined in claim 1 wherein said first comparator circuit further includes an output for providing an output indicative of whether the input voltage is within a voltage window which is less than the first threshold voltage.

Claim 7

A voltage comparator circuit for comparing an input voltage with one or more successive voltage windows, the comparator circuit comprising: a first comparator cell for comparing an input voltage with a first threshold voltage, said first comparator cell including: a first transistor and a second transistor connected as a differential input pair, the first and second transistors each having an emitter for receiving a biased current; a threshold voltage input connected to a base of the first transistor for receiving the first threshold voltage; a voltage input connected to a base of the second transistor for receiving the input voltage; a differential to single ended converter connected between a collector of the first transistor and a collector of the second transistor; and an output path coupled to a second collector of the second transistor for supplying a current when the input voltage is less than the first threshold voltage; a second comparator cell for comparing the input voltage with a second voltage threshold, said second comparator cell comprising: a first transistor and a second transistor connected as a differential input pair, the first and second transistors each having an emitter for receiving a biased current; a threshold voltage input connected to a base of the first transistor for receiving the second threshold voltage; a voltage input connected to a base of the second transistor for receiving the input voltage; an input line coupled to the output path of the first comparator cell for receiving said current when the input voltage is less than the first threshold voltage; a differential to single ended converter connected between a collector of the first transistor and a collector of the second transistor; and an output coupled to the differential to single ended converter for providing an output voltage indicative of the comparison of the input voltage with a voltage window bounded by the first and second threshold voltages.

Claim 8

A voltage comparator circuit for comparing an input voltage with one or more successive voltage windows, the comparator circuit comprising: a first comparator cell for comparing an input voltage with a first threshold voltage, said first comparator cell including: a first transistor and a second transistor connected as a differential input pair, the first and second transistors each having an emitter for receiving a biased current; a threshold voltage input connected to a base of the first transistor for receiving the first threshold voltage; a voltage input connected to a base of the second transistor for receiving the input voltage; a differential to single ended converter connected between a collector of the first transistor and a collector of the second transistor; and an output path coupled to a second collector of the second transistor for supplying a current when the input voltage is less than the first threshold voltage; a second comparator cell for comparing the input voltage with a second voltage threshold, said second comparator cell comprising: a first transistor and a second transistor connected as a differential input pair, the first and second transistors each having an emitter for receiving a biased current; a threshold voltage input connected to a base of the first transistor for receiving the second threshold voltage; a voltage input connected to a base of the second transistor for receiving the input voltage; an input line coupled to the output path of the first comparator cell for receiving said current when the input voltage is less than the first threshold voltage; a differential to single ended converter connected between a collector of the first transistor and a collector of the second transistor; and an output coupled to the differential to single ended converter for providing an output voltage indicative of the comparison of the input voltage with a voltage window bounded by the first and second threshold voltages.

Claim 9

The voltage comparative circuit as defined in claim 6 wherein the second comparator cell further comprises an output path coupled to a second collector of the second transistor for supplying a current when the input voltage is less than the second voltage threshold.

Claim 10

The voltage comparator circuit as defined in claim 7 further comprising a third comparator cell for comparing the input voltage with a third voltage threshold, said third comparator cell comprising: a first transistor and a second transistor connected as a differential input pair, the first and second transistors each having an emitter for receiving a biased current; a threshold voltage input connected to a base of the first transistor for receiving the third threshold voltage; a voltage input connected to a base of the second transistor for receiving the input voltage; an input line coupled to the output path of the second comparator cell for receiving the current when the input voltage is less than the second threshold voltage; a differential to single ended converter connected between a collector of the first transistor and a collector of the second transistor; and an output coupled to the differential to single ended converter for providing an output voltage indicative of the comparison of the input voltage with a voltage window bounded by the second and third threshold voltages.

Claim 11

The voltage comparator circuit as defined in claim 6 wherein said first comparator cell further includes an output coupled to the differential to single ended converter for producing an output signal indicative of whether the input voltage is within a voltage window which is less than the first threshold voltage.

Claim 12

A successive voltage window comparator circuit for comparing an input voltage with a series of successive voltage windows, said comparator circuit comprising: a series of interconnected comparator circuit cells for receiving predetermined respective threshold voltages and defining a series of successive voltage windows and receiving a common input voltage, each comparator circuit cell further including an output for providing an output voltage indicative of a comparison of the input voltage with the successive voltage windows, each comparator circuit cell including: a first transistor and a second transistor connected as a differential input pair, the first and second transistors each having an emitter for receiving a biased current; a threshold voltage input connected to a base of the first transistor for receiving one of said respective threshold voltages; a voltage input connected to a base of the second transistor for receiving the input voltage; a differential to single ended converter connected between a collector of the first transistor and a collector of the second transistor; an output coupled to the differential to single ended converter for providing an output signal indicative of the comparison of the input with the respective threshold voltage; and an output path coupled to a second collector of the second transistor for supplying a current to the next highest successive comparator circuit cell when the input voltage is less than the respective threshold voltage.

Claim 13

A successive voltage window comparator circuit for comparing an input voltage with a series of successive voltage windows, said comparator circuit comprising: a series of interconnected comparator circuit cells for receiving predetermined respective threshold voltages and defining a series of successive voltage windows and receiving a common input voltage, each comparator circuit cell further including an output for providing an output voltage indicative of a comparison of the input voltage with the successive voltage windows, each comparator circuit cell including: a first transistor and a second transistor connected as a differential input pair, the first and second transistors each having an emitter for receiving a biased current; a threshold voltage input connected to a base of the first transistor for receiving one of said respective threshold voltages; a voltage input connected to a base of the second transistor for receiving the input voltage; a differential to single ended converter connected between a collector of the first transistor and a collector of the second transistor; an output coupled to the differential to single ended converter for providing an output signal indicative of the comparison of the input with the respective threshold voltage; and an output path coupled to a second collector of the second transistor for supplying a current to the next highest successive comparator circuit cell when the input voltage is less than the respective threshold voltage.