Ringing suppressor circuit

Patent metadata

Field	Value
Publication number	US-10693451-B2
Application number	US-201916273810-A
Country	US
Kind code	B2
Filing date	Feb 12, 2019
Priority date	Mar 16, 2018
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A ringing suppressor circuit is connected to a differential signal transmission line that includes a high potential signal line and low potential signal line pair for transmitting high and low level differential signals, and includes a ringing suppressor and a stopper. When the differential signal changes to a high level, the ringing suppressor suppresses ringing by lowering the impedance between the signal lines by turning ON of a switching element. When a differential signal voltage drops below a voltage lowering determination voltage, the stopper stops the impedance lowering function of the ringing suppressor by turning OFF another switching element.

First claim

What is claimed is:

1. A ringing suppressor circuit connected to a transmission line for transmitting a differential signal that switches between a high level and a low level via a high potential and low potential pair of signal lines, and for suppressing a ringing in the differential signal, the ringing suppressor circuit comprising:
a ringing suppressor configured to lower an impedance between the pair of signal lines when the differential signal switches from the low level to the high level; and
a stopper configured to
stop the ringing suppressor from lowering the impedance between the pair of signal lines when the stopper determines that a voltage of the differential signal drops below a voltage lowering determination voltage, wherein
the stopper is further configured to set the voltage lowering determination voltage lower than a differential voltage of the differential signal when the transmission line is transmitting the differential signal at the high level.

2. The ringing suppressor circuit of claim 1 , wherein
the ringing suppressor is further configured to lower the impedance between the pair of signal lines for a preset amount of time.

3. The ringing suppressor circuit of claim 1 , wherein
the ringing suppressor is further configured to
detect a ringing in the differential signal when the differential signal switches from the low level to the high level, and
lower the impedance between the pair of signal lines when the ringing in the differential signal is detected.

4. The ringing suppressor circuit of claim 3 , wherein
the ringing suppressor is further configured to
determine that the ringing is caused when the differential voltage exceeds a ringing determination voltage, and
set the ringing determination voltage to be equal to or greater than the differential voltage when the transmission line is transmitting the differential signal at the high level.

Assignees

• Soken Inc
• Denso Corp

Inventors

• SEKIYA Youhei
• Mori Hiroyuki
• Kishigami Tomohisa

Classifications

• H04L12/40006

  Architecture of a communication node (current supply arrangements H04L12/10; intermediate storage or scheduling H04L49/90) · CPC title

• H04L25/026

  Arrangements for coupling transmitters, receivers or transceivers to transmission lines; Line drivers (duplexing arrangements H04L5/14) · CPC title

• H03H11/245

  using field-effect transistor · CPC title

• H04L25/0272

  Arrangements for coupling to multiple lines, e.g. for differential transmission · CPC title

• H04B3/42

  Circuits for by-passing of ringing signals · CPC title