Apparatus and method for generating an envelope for data signals using CMOS

• US 6,087,860 A
• Filed: 10/14/1998
• Issued: 07/11/2000
• Est. Priority Date: 10/14/1998
• Status: Expired due to Fees

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Cheng, Yi, Liu, Zhenhua
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): Nguyen, Hai L.
• Application Number:
  US09/172,089
• Time in Patent Office: 636 Days
• Field of Search: 327/65, 327/306, 327/52, 327/62, 327/63
• US Class Current: 327/65
• CPC Class Codes: H03K 5/02 by amplifying H03K5/04 takes precedence
• CPC Class Codes: H04L 25/0272 Arrangements for coupling to multiple lines, e.g. for differential transmission
• CPC Class Codes: H04L 25/0292 Arrangements specific to the receiver end

Abstract

A CMOS device for generating a waveformn envelope is provided in a network that uses a twisted pair medium, such as a telephone line, to connect stations. The CMOS device receives analog signals representing pulsed data signals sent over the telephone line and generates an envelope waveform for the received analog signal. The envelope waveform can then be used to detect the arrival of data, as opposed to noise on the network.

Claims

1. A CMOS device configured for receiving data transmitted over a twisted pair medium, comprising:

a receive device configured to receive an analog signal transmitted over the twisted pair medium; and

an envelope generator configured to generate an envelope waveform based on the received analog signal, wherein

the envelope generator comprises;

a differential amplifier configured to receive the analog signal and generate an amplified differential signal therefrom; and

a charge pump circuit coupled to the differential amplifier and configured to receive the amplified differential signal and generate a peak signal waveform therefrom.

2. The CMOS device of claim 1, comprising wherein the envelope generator further comprises:

a filter circuit having an input coupled to the charge pump circuit and configured to filter the peak signal waveform and generate the envelope waveform.

3. The CMOS device of claim 2, wherein the filter circuit comprises:

an operational amplifier having an input coupled to the charge pump circuit and configured to receive the peak signal waveform; and

an RC circuit coupled to the operational amplifier configured to filter out noise and harmonic components from the peak signal waveform and generate the envelope waveform.

4. The CMOS device of claim 1, wherein the charge pump circuit comprises:

first and second comparators configured to compare the amplified differential signal to the peak signal waveform output from the charge pump circuit; and

control logic configured to charge and discharge a capacitor based on the output from the first and second comparators.

5. The CMOS device of claim 1, wherein the analog signal represents data from a group of pulsed data signals.

6. The CMOS device of claim 1, wherein the envelope generator is formed on a single chip.

7. The CMOS device of claim 1, wherein the twisted pair medium comprises telephone line wiring.

8. In a network station that includes a CMOS device for receiving and transmitting data over a twisted pair medium, a method of generating a waveform envelope, comprising:

receiving an analog signal transmitted over the twisted pair medium; and

generating an envelope waveform for the received analog signal, wherein the generating step comprises;

amplifying the received analog signal; and

inputting the amplified signal to a charge pump circuit, and

generating in the charge pump circuit, a peak signal waveform.

9. The method of claim 8, further comprising wherein the generating step further comprises:

filtering the peak signal waveform to generate the envelope waveform.

10. The method of claim 9, wherein the filtering step comprises:

inputting the peak signal waveform to an operational amplifier coupled to an RC filter circuit; and

outputting the envelope waveform.

11. The method of claim 8, wherein the analog signal represents data from a group of pulsed data signals.

12. The method of claim 8, wherein generating the envelope waveform is performed on a single chip.

13. The method of claim 8, wherein the twisted pair medium comprises telephone line wiring.

14. A CMOS device, provided in a network station connected to a network employing a telephone line medium to connect network stations, comprising:

a receive device configured to receive an analog signal transmitted over the telephone line, wherein the analog signal represents a group of data signals sent from another network station; and

an envelope generator configured to generate an envelope waveform based on the received analog signal, wherein

the envelope generator comprises;

a differential amplifier configured to receive the analog signal and generate an amplified differential signal; and

a charge pump circuit coupled to the differential amplifier and configured to receive the amplified differential signal and generate a peak signal waveform.

15. The CMOS device of claim 14, wherein the envelope generator further comprises:

a filter circuit having an input coupled to the charge pump circuit and configured to filter the peak signal waveform and generate the envelope waveform.

16. The CMOS network device of claim 15, wherein the charge pump circuit comprises:

first and second comparators configured to compare the amplified differential signal to the peak signal waveform output from the charge pump circuit; and

control logic configured to charge and discharge a capacitor based on the output from the first and second comparators.