Device including a plurality of analog circuits and an interface that matches characteristics of the analog circuits

• US 9,042,858 B2
• Filed: 05/23/2013
• Issued: 05/26/2015
• Est. Priority Date: 07/20/2010
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Mikhemar, Mohyee, Hadji-Abdolhamid, Amir, Darabi, Hooman
• Primary Examiner(s): Jackson, Blane J
• Application Number:
  US13/901,500
• Publication Number:
  US 20130259163A1
• Time in Patent Office: 733 Days
• Field of Search: 455/226.1, 455/232.1, 455/296, 455/307, 455/334
• US Class Current: 455/307
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/086 with FET's
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/91 the amplifier has a current mode topology
• CPC Class Codes: H03F 2203/45332 the AAC comprising one or more capacitors as feedback circuit elements
• CPC Class Codes: H03F 2203/45336 the AAC comprising one or more resistors as feedback circuit elements
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/45076 characterised by the way of implementation of the active amplifying circuit in the differential amplifier
• CPC Class Codes: H03G 1/0005 Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal
• CPC Class Codes: H03G 1/0029 using FETs
• CPC Class Codes: H03G 3/3068 Circuits generating control signals for both R.F. and I.F. stages
• CPC Class Codes: H03G 3/32 the control being dependent upon ambient noise level or sound level
• CPC Class Codes: H03H 11/1217 using a plurality of operational amplifiers H03H11/1204 takes precedence; parallel-T filters H03H11/1295
• CPC Class Codes: H03H 11/1252 Two integrator-loop-filters
• CPC Class Codes: H03H 11/1256 Tow-Thomas biquad
• CPC Class Codes: H03H 11/1291 Current or voltage controlled filters
• CPC Class Codes: H03H 2210/025 Capacitor
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04L 25/06 : Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection

Abstract

According to one embodiment, a compact low-power receiver comprises first and second analog circuits connected by a digitally controlled interface circuit. The first analog circuit has a first direct-current (DC) offset and a first common mode voltage at an output, and the second analog circuit has a second DC offset and a second common mode voltage at an input. The digitally controlled interface circuit connects the output to the input, and is configured to match the first and second DC offsets and to match the first and second common mode voltages. In one embodiment, the first analog circuit is a variable gain control transimpedance amplifier (TIA) implemented using a current mode buffer, the second analog circuit is a second-order adjustable low-pass filter, whereby a three-pole adjustable low-pass filter in the compact low-power receiver is effectively produced.

Claims

1. An electronic device comprising:

a first analog circuit having a first direct current (DC) offset at an output;

a second analog circuit having a second DC offset at an input;

an interface circuit connecting said output to said input and configured to match said first and second DC offsets.

2. The electronic device of claim 1, further comprising:

an analog-to-digital converter (ADC) coupled to an output of said second analog circuit.

3. The electronic device of claim 2, wherein said ADC is configured to provide control data for said interface circuit.

4. The electronic device of claim 1, wherein said interface circuit comprises a plurality of cross-coupled adjustable current source pairs.

5. The electronic device of claim 4, wherein said plurality of cross-coupled adjustable current source pairs are configured to tune at least one internal current of said interface circuit so as to match said first and second DC offsets.

6. The electronic device of claim 4, wherein said plurality of cross-coupled adjustable current source pairs are configured to tune at least one internal current of said interface circuit so as to match a first common mode voltage at said output and a second common mode voltage at said input.

7. The electronic device of claim 1, wherein said first analog circuit comprises a variable gain control transimpedance amplifier implemented using a current mode buffer.

8. The electronic device of claim 1, wherein said second analog circuit comprises a two-pole adjustable low-pass filter.

9. The electronic device of claim 1, wherein said first and second analog circuits together function as a three-pole low-pass Chebyshev filter.

10. An electronic device comprising:

a first analog circuit having a first common mode voltage at an output;

a second analog circuit having a second common mode voltage at an input;

an interface circuit connecting said output to said input and configured to match said first and second common mode voltages.

11. The electronic device of claim 10, further comprising an analog-to-digital converter (ADC) coupled to an output of said second analog circuit.

12. The electronic device of claim 11, wherein said ADC is configured to provide control data for said interface circuit.

13. The electronic device of claim 11, wherein said interface circuit comprises a plurality of cross-coupled adjustable current source pairs.

14. The electronic device of claim 13, wherein said plurality of cross-coupled adjustable current source pairs are configured to tune at least one internal current of said interface circuit so as to match a first direct-current (DC) offset at said output and a second DC offset at said input.

15. The electronic device of claim 13, wherein said plurality of cross-coupled adjustable current source pairs are configured to tune at least one internal current of said interface circuit so as to match said first and second common mode voltages.

16. The electronic device of claim 11, wherein said first analog circuit comprises a variable gain control transimpedance amplifier implemented using a current mode buffer.

17. The electronic device of claim 11, wherein said second analog circuit comprises a two-pole adjustable low-pass filter.

18. The electronic device of claim 11, wherein said first and second analog circuits together function as a three-pole low-pass Chebyshev filter.

19. An electronic device comprising:

a first analog circuit;

a second analog circuit; and

an interface connecting an output of the first analog circuit to an input of the second analog circuit, wherein

the interface is configured to match at least one of

a first direct-current (DC) offset at an output of the first analog circuit and a second DC offset at an input of the second analog circuit; and

a first common mode voltage at the output of the first analog circuit and a second common mode voltage at the input of the second analog circuit.

20. The electronic device of claim 19, wherein the first analog circuit is a variable gain control transimpedance amplifier and the second analog circuit us a second-order adjustable low-pass filter.

21. The electronic device of claim 19, wherein the interface is controlled by an output of an analog-to-digital converter (ADC) coupled to an output of said second analog circuit.