IP Library › Granted Patent US 7,286,013
Granted Patent B2
US 7,286,013 · App. 10/667,019 · Granted Oct 23, 2007

Coupled-inductance differential amplifier

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,286,013
App. No.
10/667,019
Granted
Oct 23, 2007
Kind
B2
Abstract

A differential amplifier that employs mutually coupled inductors to provide desired levels of inductance in a substantially smaller form factor in comparison to individual inductor components. Mutually coupled inductors according to the present teachings may also be used to increase common mode rejection in a differential amplifier.

Claims (22)

1. A differential amplifier, comprising:

a pair of transistors;

a pair of inductors that provide impedance matching for the differential amplifier and that are arranged such that the inductors have a mutual inductance that increases when the differential amplifier is in a common mode.

2. The differential amplifier of claim 1 , wherein the inductors comprise a transformer.

3. The differential amplifier of claim 1 , wherein the inductors are arranged to provide input impedance matching for the differential amplifier.

4. The differential amplifier of claim 1 , wherein the inductors are coupled to a source terminal of each transistor.

5. The differential amplifier of claim 1 , wherein the inductors are arranged to provide noise control for the differential amplifier.

6. The differential amplifier of claim 1 , wherein the inductors are arranged to increase common mode rejection in the differential amplifier.

7. The differential amplifier of claim 1 , further comprising a second pair of inductors that are arranged to bias the transistors.

8. The differential amplifier of claim 7 , wherein the second pair of inductors are arranged to have a mutual inductance that increases when the differential amplifier is excited in the differential mode.

9. The differential amplifier of claim 8 , wherein the second pair of inductors comprise a transformer.

10. The differential amplifier of claim 9 , wherein the second pair of inductors are arranged to provide output impedance matching.

11. A method for providing a differential amplifier, comprising providing a pair of transistors; and arranging a pair of inductors for impedance matching to the differential amplifier such that the inductors have a mutual inductance that increases when the differential amplifier is in a common mode.

12. The method of claim 11 , wherein arranging comprises arranging the inductors for form a transformer.

13. The method of claim 11 , wherein arranging comprises arranging the inductors to provide input impedance matching for the differential amplifier.

14. The method of claim 11 , wherein arranging comprises coupling the inductors to a source terminal of each transistor.

15. The method of claim 11 , wherein arranging comprises coupling the inductors to provide noise control for the differential amplifier.

16. The method of claim 11 , wherein arranging comprises coupling the inductors to increase common mode rejection in the differential amplifier.

17. The method of claim 11 , further comprising arranging a second pair of inductors that bias the transistors.

18. The method of claim 17 , wherein arranging a second pair of inductors comprises arranging the second pair of inductors to have a mutual inductance that increases when the differential amplifier is excited in the differential mode.

19. The method of claim 18 , wherein arranging a second pair of inductors comprises arranging the second pair of inductors to form a transformer.

20. The method of claim 19 , wherein arranging a second pair of inductors comprises arranging the second pair of inductors to provide output impedance matching for the differential amplifier.