Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
226 words
A sense amplifier apparatus for detecting the presence or absence of current flow through a device, which device is connected to an electrical conductor for periodically drawing current therefrom, said sense amplifier apparatus comprising: a voltage node connectable to the electrical conductor; a current source means connected to said voltage node for supplying the electrical conductor with current and for raising the voltage at said voltage node to a first predetermined voltage level, said current source means including a first transistor; a voltage source means connected to said voltage node for charging the electrical conductor to a second predetermined voltage level less than said first predetermined voltage level, said voltage source means including a second transistor having a large current and voltage capacity relative to said first transistor; and a transfer means connected between said voltage node and the electrical conductor for clamping the voltage on the electrical conductor at said second predetermined voltage level and for permitting said current source means to raise the voltage at said voltage node to said first predetermined voltage level when current is not flowing through the device while permitting the voltage at said voltage node to drop to said second predetermined voltage level when current is flowing through the device, said transfer means including a third transistor having a large current and voltage capacity relative to said first transistor.
Claim 2
Dependent Claim
226 words
A sense amplifier apparatus for detecting the presence or absence of current flow through a device, which device is connected to an electrical conductor for periodically drawing current therefrom, said sense amplifier apparatus comprising: a voltage node connectable to the electrical conductor; a current source means connected to said voltage node for supplying the electrical conductor with current and for raising the voltage at said voltage node to a first predetermined voltage level, said current source means including a first transistor; a voltage source means connected to said voltage node for charging the electrical conductor to a second predetermined voltage level less than said first predetermined voltage level, said voltage source means including a second transistor having a large current and voltage capacity relative to said first transistor; and a transfer means connected between said voltage node and the electrical conductor for clamping the voltage on the electrical conductor at said second predetermined voltage level and for permitting said current source means to raise the voltage at said voltage node to said first predetermined voltage level when current is not flowing through the device while permitting the voltage at said voltage node to drop to said second predetermined voltage level when current is flowing through the device, said transfer means including a third transistor having a large current and voltage capacity relative to said first transistor.
Claim 3
Dependent Claim
58 words
A sense amplifier apparatus as set forth in claim 1, wherein said second and third transistors both have control gates, said sense amplifier apparatus further including a reference signal generating means connected to said second and third transistors for supplying said control gates with a reference voltage which establishes said second predetermined voltage level on the electrical conductor.
Claim 4
Dependent Claim
51 words
A sense amplifier apparatus as set forth in claim 2, wherein said reference signal generating means includes a reference voltage node, an operating voltage supply, a fourth transistor connected between said reference voltage node and said operating voltage supply and a fifth transistor connected between said reference voltage node and ground.
Claim 5
Dependent Claim
25 words
A sense amplifier apparatus as set forth in claim 3, wherein said fourth and fifth transistors are both depletion-mode type transistors having grounded control gates.
Claim 6
Dependent Claim
50 words
A sense amplifier apparatus as set forth in claim 1, further including an amplifying means connected to said voltage node for sensing a voltage drop from said first predetermined voltage level to said second predetermined voltage level at said voltage node and for outputting a data signal in response thereto.