Reference current source

Patent metadata

Field	Value
Publication number	US-9720435-B2
Application number	US-201514980093-A
Country	US
Kind code	B2
Filing date	Dec 28, 2015
Priority date	Dec 28, 2015
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Systems, methods, and apparatus for generating a reference current. A reference current source can include a current generator circuit; a first resistance circuit that has a positive temperature dependence; and a second resistance circuit that has a negative temperature dependence. The first resistance circuit and the second resistance circuit can be connected in parallel to the current generator circuit.

First claim

What is claimed is:

1. A reference current source, comprising:
a current generator circuit; and
a resistance circuit connected to the current generator circuit, wherein the resistance circuit comprises a current controlled resistance circuit and a voltage controlled resistance circuit that is connected in parallel with the current controlled resistance circuit, wherein the voltage controlled resistance circuit comprises a first plurality of MOSFETs, and wherein the first plurality of MOSFETs comprise:
a first MOSFET having a drain connected to an emitter of a bipolar transistor of the current generator, and having a source connected to ground;
a second MOSFET having a drain connected to a voltage source of the current generator and a gate connected to a first current control voltage source; and
a third MOSFET having a source connected to ground and a gate connected to a second current control voltage source, wherein a drain of the third MOSFET is connected to each of a drain of the second MOSFET and a gate of the first MOSFET.

2. The reference current source of claim 1 , wherein the current controlled resistance circuit comprises a second plurality of MOSFETs.

3. The reference current source of claim 2 , wherein the second plurality of MOSFETs comprise:
a fourth MOSFET having a drain connected to each of the drain of the first MOSFET and the emitter of the bipolar transistor, and having a source connected to the ground;
a fifth MOSFET having a source connected to the voltage source of the current generator and a gate connected to the current generator; and
a sixth MOSFET having a source connected to ground and a gate connected to each of a gate of the fourth MOSFET, a drain of the fifth MOSFET, and a drain of the sixth MOSFET.

4. The reference current source of claim 1 , wherein the current controlled resistance circuit has a positive temperature dependency.

5. The reference current source of claim 4 , wherein the voltage controlled resistance circuit has a negative temperature dependency.

6. The reference current source of claim 5 , wherein the current controlled resistance circuit and the voltage controlled resistance circuit are respectively configured so that a combination of the positive temperature dependency and the negative temperature dependency configure the reference current source to be temperature independent.

7. The reference current source of claim 5 , wherein the current controlled resistance circuit and the voltage controlled resistance circuit are respectively configured so that a combination of the positive temperature dependency and the negative temperature dependency configure the reference current source to have a positive temperature dependence.

8. The reference current source of claim 5 , wherein the current controlled resistance circuit and the voltage controlled resistance circuit are respectively configured so that a combination of the positive temperature dependency and the negative temperature dependency configure the reference current source to have a negative temperature dependence.

9. The reference current source of claim 1 , wherein the current generator circuit comprises a PTAT current generator circuit.

10. A reference current source comprising:
a current generator circuit;
a current controlled resistance circuit that has a positive temperature dependence; and
a voltage controlled resistance circuit that has a negative temperature dependence, wherein the current controlled resistance circuit and the voltage controlled resistance circuit are connected in parallel to the current generator circuit, and wherein an L2/L1 ratio and a p value for MOSFETs of the reference current source are selected to provide a zero current slope at a given temperature.

11. A reference current source, comprising:
a current generator circuit; and
a resistance circuit connected to the current generator circuit, wherein the resistance circuit comprises a current controlled resistance circuit and a voltage controlled resistance circuit, the current controlled resistance circuit connected to a voltage source of the current generator circuit, the voltage controlled resistance circuit connected to the voltage source of the current generator circuit, a first current control voltage source, and a second current control voltage source.

Assignees

• Adtran Inc

Inventors

• Joffe Daniel M
• Chandler Daniel R

Classifications

• G05F3/08 Primary

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