Current source

Claim 2

A current source comprising: a field effect transistor having a drain, a source, a gate and a substrate electrodes, the gate electrode thereof being direct coupled to the drain electrode thereof; a resistive element having first and second ends direct coupled to the substrate and source electrodes of said field-effect transistors, respectively; means for coupling operating and reference potentials to separate ones of the substrate and drain electrodes of said field-effect transistor; means for sensing the drain current of said field-effect transistor flowing in response to said operating potential and for responding to the sensed said drain current to provide an output current; and means for utilizing said output current.

Claim 3

A current source as claimed in claim 1 wherein: a potential divider included in said means for coupling potentials receives said operating and reference potentials and supplies a potential intermediate therebetween to the first end of said resistive element, and said resistive element has its second end directly connected to said field effect transistor source electrode.

Claim 4

A current source as claimed in claim 1 wherein said means for sensing the drain current of said field-effect transistor flowing in response to said operating potential and for respoNding to the sensed said drain current to provide an output current comprises: a first and a second semiconductor amplifier devices having common electrodes each connected to receive said reference potential, having output electrodes respectively coupled to said field-effect transistor drain electrode and to said utilizing means, and having input electrodes coupled from said first amplifier device output electrode.

Claim 5

A current source as claimed in claim 1 wherein said means for sensing the drain current of said field-effect transistor flowing in response to said operating potential and for responding to the sensed said drain current to provide an output current comprises: a first and a second bipolar transistors having emitter electrodes each connected to receive said reference potential, having collector electrodes respectively coupled to said field-effect transistor drain electrode and to said utilizing means, and having base electrodes coupled from said first transistor collector electrode.

Claim 6

A current source as claimed in claim 4 wherein: a further field-effect transistor has a drain and a source electrodes with a path therebetween providing said coupling between said field effect transistor drain electrode and said first bipolar transistor collector electrode, has a gate electrode coupled from its said drain electrode and has a substrate electrode coupled to its said source electrode.

Claim 7

A current source comprising: means for supplying operating and reference potentials; a field effect transistor having a drain and a source electrodes and a drain-to-source path therebetween, having a gate electrode coupled from its said drain electrode, and having a substrate electrode coupled to its said source electrode, a first and a second bipolar transistor devices having emitter electrodes each connected to receive said reference potential, having collector electrodes and having base electrodes each coupled from said first transistor collector electrode; means for coupling said first transistor collector electrode to receive said operating potential including said drain-to-source path of said field effect transistor; and utilization means connected to said second transistor collector electrode and adapted for the collector current flow of said second transistor therethrough.

Claim 8

A current source comprising: means for supplying operating and reference potentials; a field effect transistor having a drain and a source electrodes and a drain-to-source path therebetween, having a gate electrode coupled from its said drain electrode, and having a substrate electrode coupled to its said source electrode, a first and a second bipolar transistor devices having emitter electrodes each connected to receive said reference potential, having collector electrodes and having base electrodes each coupled from said first transistor collector electrode; means for coupling said first transistor collector electrode to receive said operating potential including said drain-to-source path of said field effect transistor; and utilization means connected to said second transistor collector electrode and adapted for the collector current flow of said second transistor therethrough.

Claim 9

A current source comprising: a first and a second terminals for application of separate ones of an operating and a reference potentials, respectively, a first field effect transistor formed on a substrate and having a drain, a source, a gate, and a substrate electrodes, the gate electrode thereof being direct coupled to the drain electrode thereof, the substrate electrode thereof being connected to said first terminal; a first and a second resistive elements being serially coupled between said first and said second terminals and having an interconnection between them; means direct current conductively coupling said first field effect transistor source electrode to said interconnection; and current amplifier means having an input circuit connecting said first field effect transistor drain electrode to said second terminal and having an output circuit from which output current is provided.

Claim 10

A current source comprising: a first and a second terminals for application of separate ones of an operating and a reference potentials, respectively, a first field effect transistor formed on a substrate and having a drain, a source, a gate, and a substrate electrodes, the gate electrode thereof being direct coupled to the drain electrode thereof, the substrate electrode thereof being connected to said first terminal; a first and a second resistive elements being serially coupled between said first and said second terminals and having an interconnection between them; means direct current conductively coupling said first field effect transistor source electrode to said interconnection; and current amplifier means having an input circuit connecting said first field effect transistor drain electrode to said second terminal and having an output circuit from which output current is provided.

Claim 11

A current source as claimed in claim 7 wherein: a third resistive element is included in said means direct current conductively coupling said first field effect transistor source electrode to said interconnection.

Claim 12

A current source as claimed in claim 7 wherein: said current amplifier comprises: an output terminal and a second and a third field effect transistors of complementary conductivity type to that of said first field effect transistor, each having a source and a substrate electrodes connected to said second terminal, having drain electrodes respectively coupled to said first field effect transistor drain electrode and to said output terminal and each having gate electrodes coupled from said second field effect trAnsistor drain electrode.

Claim 13

A current source as claimed in claim 7 wherein said current amplifier comprises: an output terminal and a first and a second bipolar transistors each having an emitter electrode connected to said second terminal, having collector electrodes respectively coupled to said first field effect transistor drain electrode and to said output terminal and each having a base electrode coupled from said first bipolar transistor collector electrode.

Claim 14

In combination: a field effect transistor having source, drain, gate and substrate electrodes, connected gate-to-drain; voltage supply terminals coupled to said source and drain electrodes, respectively, for supplying an operating voltage to said transistor; and biasing means coupled between said source and substrate electrodes and responsive to said operating voltage for supplying a reverse bias voltage between said source and substrate electrode which varies with variations in said operating voltage at a rate and in a sense to tend to maintain constant the source-to-drain current of said transistor.

Claim 15

In combination: a field effect transistor having source, drain, gate and substrate electrodes, connected gate-to-drain; voltage supply terminals coupled to said source and drain electrodes, respectively, for supplying an operating voltage to said transistor; and biasing means coupled between said source and substrate electrodes and responsive to said operating voltage for supplying a reverse bias voltage between said source and substrate electrode which varies with variations in said operating voltage at a rate and in a sense to tend to maintain constant the source-to-drain current of said transistor.

Claim 16

The combination of claim 11 wherein said biasing means includes: means for providing a potential proportional to and smaller than said operating potential and means for coupling said proportional potential between said source and said substrate electrodes.

Claim 17

The combination of claim 12 wherein said means for coupling said proportional potential between said source and said substrate electrodes includes: a resistive element coupling said source electrode to said means for providing a potential proportional to and smaller than said operating potential.

Claim 18

The combination of claim 11 wherein said biasing means comprises: a potential divider having an input circuit connected between said voltage supply terminals, a first output circuit direct coupled between said substrate and said source electrodes, and a second output circuit direct coupled between said source and said drain electrodes.

Claim 19

The combination of claim 14 wherein said potential divider further includes a common connection between its said first and said second output circuits and a resistive element links said common connection to said substrate electrode.

Claim 20

The combination of claim 15 wherein said resistive element comprises a diode connected further field-effect transistor.