AC coupled single-ended LVDS receiving circuit comprising low-pass filter and voltage regulator

Patent metadata

Field	Value
Publication number	US-9459648-B2
Application number	US-201113814485-A
Country	US
Kind code	B2
Filing date	Aug 5, 2011
Priority date	Aug 5, 2010
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A receiving circuit is provided that can accurately detect a clock signal that has a single phase and a small amplitude. A receiving circuit includes an AC coupled circuit 22 that creates an AC coupling between a first end and a second end, a low-pass filter circuit 23, 25 that produces a third signal by applying a low-pass filtering on a second signal that is produced on the second end in response to a first signal that is applied to the first end, and a comparator 21 that inputs the second signal and the third signal.

First claim

The invention claimed is:

1. A receiving circuit comprising:
an AC-coupled circuit configured to create an AC coupling between a first end and a second end;
a low-pass filter circuit configured to, in response to a first signal that is applied to the first end, apply a low-pass filtering on a second signal that is produced on the second end to produce a reference signal;
a comparator configured to receive an input of the second signal and the reference signal to produce an output signal; and
a voltage-regulating circuit configured to match a voltage value of the second signal to a common-mode voltage rating of the comparator, wherein the voltage regulating circuit includes a series of resistors disposed between a power source voltage and a ground voltage.

2. The receiving circuit according to claim 1 , wherein the comparator is a low voltage differential signaling (LVDS) receiver.

3. The receiving circuit according to claim 1 , wherein the series of resistors comprises:
a first resistor connected between the power source voltage and a first input end of the LVDS receiver,
a second resistor connected between the first input end and a second input end of the LVDS receiver, and
a third resistor element connected between the second input end and the ground voltage.

4. The receiving circuit according to claim 1 , wherein the AC coupled circuit includes a capacitive element.

5. The receiving circuit according to claim 1 , wherein the low-pass filter circuit includes a resistor element and a capacitive element.

6. The receiving circuit according to claim 1 , wherein the AC coupled circuit includes a transformer.

7. A signal transmitting circuit, comprising:
a single-phase transmitting wiring;
a damping resistor interposed in the transmitting wiring;
an AC-coupled circuit configured to create an AC coupling between a first end and a second end, the first end connected to a receiving side of the transmitting wiring;
a low-pass filter circuit configured to, in response to a first signal that is applied to a first end, apply a low-pass filtering on a second signal that is produced on the second end to produce a reference signal;
a comparator configured to receive an input of the second signal and the reference signal to produce an output signal; and
a voltage-regulating circuit configured to match a voltage value of the second signal to a common-mode voltage rating of the comparator, wherein the voltage regulating circuit includes a series of resistors disposed between a power source voltage and a ground voltage.

8. The signal transmitting circuit according to claim 7 , wherein the comparator is a low voltage differential signaling (LVDS) receiver.

9. A signal receiving method, comprising the steps of:
extracting AC components from a received signal;
adding the AC components with a voltage regulating circuit to produce a first voltage signal that matches a common-mode voltage rating of a comparator, wherein the voltage regulating circuit includes a series of resistors disposed between a power source voltage and a ground voltage;
applying a low-pass filtering on the first voltage signal to produce a reference voltage signal; and
comparing the first voltage signal and the reference voltage signal at the comparator to produce an output signal.

Assignees

• Kanamaru Hiroki
• Gvbb Holdings Sarl

Inventors

• Kanamaru Hiroki

Classifications

• H04L25/0294

  Provision for current-mode coupling · CPC title

• G05F5/00 Primary

  Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output · CPC title

• H04L25/0276

  Arrangements for coupling common mode signals · CPC title

• H04L25/0298

  Arrangement for terminating transmission lines · CPC title