Adjustable temperature dependent current generator

Claim 2

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant; first means for generating current I 1 as a function of temperature; second means for generating current I 4 as a function of temperature, wherein the first and second current generating means produce equal and opposite changes in I 1 and I 4 such that currents I 1 and I 4 bear a relationship to temperature of: (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4)=K(T-T.sub.o), where, K is a constant, T o is an arbitrary temperature and T is a measure of the current generator temperature; and means for controlling currents I 2 and I 3 independent of temperature such that G c is adjusted independent of temperature whereby the current generator has an adjustable gain, G c .

Claim 3

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant; first means for generating current I 1 as a function of temperature, the first current generating means including a second circuit comprising part of the current path through with I 1 flows including a transistor Q 7 with a base, an emitter, and a base-emitter voltage, a temperature independent voltage source supplying a voltage V bg to the base of transistor Q 7 , and a resistor R 1 , with a voltage, connected between the emitter of transistor Q 7 and a ground, the base-emitter voltage of transistor Q 7 changing in relation to temperature thereby altering the voltage across R 1 and current I 1 in relation to temperature; second means for generating current I 4 as a function of temperature, the second current generating means including a third circuit comprising part of the current path through which I 4 flows including two transistors, Q 8 and Q 9 , Q 9 having a base and a base-emitter voltage, a temperature independent current source forward biasing transistor Q 8 , and a resistor R 4 , with a voltage, connected between the base of transistor Q 9 and ground, the base-emitter voltage of transistor Q 9 changing in relation to temperature thereby altering the voltage across R 4 and current I 4 in relation to temperature; and means for controlling currents I 2 and I 3 independent of temperature such that G c is adjusted independent of temperature whereby the current generator has an adjustable gain, G c .

Claim 4

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant; first means for generating current I 1 as a function of temperature, the first current generating means including a second circuit comprising part of the current path through with I 1 flows including a transistor Q 7 with a base, an emitter, and a base-emitter voltage, a temperature independent voltage source supplying a voltage V bg to the base of transistor Q 7 , and a resistor R 1 , with a voltage, connected between the emitter of transistor Q 7 and a ground, the base-emitter voltage of transistor Q 7 changing in relation to temperature thereby altering the voltage across R 1 and current I 1 in relation to temperature; second means for generating current I 4 as a function of temperature, the second current generating means including a third circuit comprising part of the current path through which I 4 flows including two transistors, Q 8 and Q 9 , Q 9 having a base and a base-emitter voltage, a temperature independent current source forward biasing transistor Q 8 , and a resistor R 4 , with a voltage, connected between the base of transistor Q 9 and ground, the base-emitter voltage of transistor Q 9 changing in relation to temperature thereby altering the voltage across R 4 and current I 4 in relation to temperature; and means for controlling currents I 2 and I 3 independent of temperature such that G c is adjusted independent of temperature whereby the current generator has an adjustable gain, G c .

Claim 5

The current generator in claim 2 wherein (1) transistors Q 7 and Q 9 are substantially identical, (2) resistors R 1 and R 4 are substantially identical, and (3) voltage V bg is substantially twice the base-emitter voltages of Q 7 and Q 9 at a predetermined temperature, T o , such that, as temperature, T, changes, the relation of I 1 and I 4 changes in the manner: (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4)=K(T-T.sub.o), where K is a constant.

Claim 6

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant; first means for generating current I 1 as a function of temperature; second means for generating current I 4 as a function of temperature; and means for controlling currents I 2 and I 3 independent of temperature, including an adjustable temperature independent constant current source, coupled between transistors Q 2 and Q 3 and ground, and supplying a current, I x , substantially equal to the sum of currents I 2 and I 3 , where current I x is substantially directly proportional to G c , such that G c is adjustable independent of temperature whereby the current generator has an adjustable gain, G c .

Claim 7

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant; first means for generating current I 1 as a function of temperature; second means for generating current I 4 as a function of temperature; and means for controlling currents I 2 and I 3 independent of temperature, including an adjustable temperature independent constant current source, coupled between transistors Q 2 and Q 3 and ground, and supplying a current, I x , substantially equal to the sum of currents I 2 and I 3 , where current I x is substantially directly proportional to G c , such that G c is adjustable independent of temperature whereby the current generator has an adjustable gain, G c .

Claim 8

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant; first means for generating current I 1 as a function of temperature, including a second circuit comprising part of the current path through with I 4 flows including a transistor Q 7 with a base, and emitter, and a base-emitter voltage, a temperature independent voltage source supplying a voltage V bg to the base of transistor Q 7 , and a resistor R 1 , with a voltage, connected between the emitter of transistor Q 7 and a ground, the base-emitter voltage of transistor Q 7 changing as a function of temperature thereby altering the voltage across R 1 and current I 4 in response to temperature; second means for generating current I 4 as a function of temperature, including a third circuit comprising part of the current path through which I 1 flows including two transistors Q 8 and Q 9 , Q 9 having a base and a base-emitter voltage, a temperature independent current source forward biasing transistor Q 8 , and a resistor R 4 , with a voltage, connected between the base of transistor Q 9 and ground, the base-emitter voltage of transistor Q 9 changing as a function of temperature thereby altering the voltage across R 4 and current I 4 in response to temperature; and means for controlling currents I 2 and I 3 independent of temperature such that G c is adjusted independent of temperature whereby the current generator has an adjustable gain, G c .

Claim 9

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant; first means for generating current I 1 as a function of temperature, including a second circuit comprising part of the current path through with I 4 flows including a transistor Q 7 with a base, and emitter, and a base-emitter voltage, a temperature independent voltage source supplying a voltage V bg to the base of transistor Q 7 , and a resistor R 1 , with a voltage, connected between the emitter of transistor Q 7 and a ground, the base-emitter voltage of transistor Q 7 changing as a function of temperature thereby altering the voltage across R 1 and current I 4 in response to temperature; second means for generating current I 4 as a function of temperature, including a third circuit comprising part of the current path through which I 1 flows including two transistors Q 8 and Q 9 , Q 9 having a base and a base-emitter voltage, a temperature independent current source forward biasing transistor Q 8 , and a resistor R 4 , with a voltage, connected between the base of transistor Q 9 and ground, the base-emitter voltage of transistor Q 9 changing as a function of temperature thereby altering the voltage across R 4 and current I 4 in response to temperature; and means for controlling currents I 2 and I 3 independent of temperature such that G c is adjusted independent of temperature whereby the current generator has an adjustable gain, G c .

Claim 10

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant, the transconductance current multiplier additionally comprising three transistors, Q 11 , Q 12 , and Q 13 , wherein the transconductance current multiplier is a four quadrant transconductance current multiplier, the tree transistors in part defining three additional current paths through which three additional currents, I 11 , I 12 , I 13 , flow, the current I 11 being substantially equal to current I 1 , first means for generating current I 1 as a function of temperature; second means for generating current I 4 as a function of temperature; means for controlling currents I 2 and I 3 independent of temperature and for controlling currents I 12 and I 13 independent of temperature and independent of currents I 2 and I 3 , such that G c is adjustable independent of temperature whereby the current generator has an adjustable gain, G c ; and third means for generating current I 11 as a function of temperature.

Claim 11

A current generator for supplying an output current with adjustable temperature dependence, comprising: a first circuit including (1) a transconductance current multiplier comprising four transistors, Q 1 , Q 2 , Q 3 , and Q 4 , the four transistors in part defining four primary current paths through with four primary currents, I 1 , I 2 , I 3 , and I 4 , flow (2) a current mirror comprising transistors Q 5 and Q 6 coupled to the transconductance current multiplier, transistor Q 5 connected to transistor Q 2 and transistor Q 6 connector to transistor Q 3 , and (3) an output current path, coupled to the connection of transistor Q 3 to transistor Q 6 , through which the output current, I t , flows, the output current substantially bearing a relation to the two primary currents I 1 and I 4 such that: I.sub.t =G.sub.c (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4), where G c is a constant, the transconductance current multiplier additionally comprising three transistors, Q 11 , Q 12 , and Q 13 , wherein the transconductance current multiplier is a four quadrant transconductance current multiplier, the tree transistors in part defining three additional current paths through which three additional currents, I 11 , I 12 , I 13 , flow, the current I 11 being substantially equal to current I 1 , first means for generating current I 1 as a function of temperature; second means for generating current I 4 as a function of temperature; means for controlling currents I 2 and I 3 independent of temperature and for controlling currents I 12 and I 13 independent of temperature and independent of currents I 2 and I 3 , such that G c is adjustable independent of temperature whereby the current generator has an adjustable gain, G c ; and third means for generating current I 11 as a function of temperature.

Claim 12

The current generator in claim 6 wherein the first, second and third current generating means produce substantially equal and opposite changes in currents I 1 and I 4 and substantially equal changes in currents I 1 and I 11 such that currents I 1 and I 4 bear a relationship to temperature of: (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4)=K(T-T.sub.o), where K is a constant, T o is a predetermined temperature and T is a measure of the current generator temperature.

Claim 13

The current generator in claim 6 wherein: the first and third current generating means include a second circuit comprising part of the current paths through which currents I 1 and I 11 flow including two transistors Q 7 and Q 17 , each with a base, an emitter, and a base-emitter voltage, a temperature independent voltage source supplying a voltage V bg to the base of transistors Q 7 and Q 17 , and two resistors R 1 and R 11 , with voltages, R 1 connected between the emitter of Q 7 and a ground and R 11 connected between the emitter of Q 17 and ground, the base-emitter voltages of transistors Q 7 and Q 17 changing in relation to temperature thereby altering the voltages across R 1 and R 11 and current I 1 and I 11 in relation to temperature; and the second current generating means includes a third circuit comprising part of the current path through which I 4 flows including two transistors, Q 8 and Q 9 , Q 9 having a base and a base-emitter voltage, a temperature independent current source forward biasing transistor Q 8 , and a resistor R 4 , with a voltage, connected between the base of transistor Q 9 and ground, the base-emitter voltage of transistor Q 9 changing in relation to temperature thereby altering the voltage across R 4 and current I 4 in relation to temperature.

Claim 14

The current generator in claim 8 wherein (1) transistors Q 7 , Q 17 and Q 9 are substantially identical, (2) resistors R 1 , R 11 and R 4 are substantially identical, and (3) voltage V bg equals twice the base-emitter voltages of Q 7 , Q 17 and Q 9 at a predetermined temperature, T o , such that, as temperature, T, changes, the relation of I 1 and I 4 changes in the manner: (I.sub.4 -I.sub.1)/(I.sub.1 +I.sub.4)=K(T-T.sub.o), where K is a constant.

Claim 15

The current generator in claim 6 wherein the current controlling means includes first and second adjustable temperature independent constant current sources, the first current source, coupled between transistors Q 2 and Q 3 and ground, supplying a current, I x , substantially equal to the sum of currents I 2 and I 3 , the second current source, coupled between transistors Q 12 and Q 13 and ground, supplying a current, I y , substantially equal to the sum of currents I 12 and I 13 , where a current difference, (I x -I y ), is substantially directly proportional to G c .