Ringing suppression circuit

A ringing suppression circuit connecting to a transmission line for transmitting a differential signal changed into a high level or a low level as one of binary levels through a pair of signal lines to suppress ringing occurred with a transmission of the differential signal, the ringing suppression circuit comprising:

• a single line switching element, which is driven by a voltage, that is connected between the pair of signal lines;
• a controller that detects a change in a level of the differential signal and turns on the single line switching element to lower an impedance between the pair of signal lines;
• a period detector that detects a length of a suppressing period indicated by a setting signal, which is an input;
• and
• a suppressing period storage that stores the length of the suppressing period which is detected by the period detector,
• wherein the pair of signal lines includes a high potential signal line and a low potential signal line,
• wherein the controller turns on the single line switching element for only the suppressing period having the length, which is stored in the suppressing period storage,
• wherein the setting signal indicates the length of the suppressing period as a pulse width, and
• wherein the period detector includes:
• a power source supply detector that detects a start of a power source supply;
• an edge detector that detects a falling edge of a pulse of the setting signal;
• an enable signal output device
• sets a setting enable signal to an active level with a detection of the start of the power source supply as a trigger, and
• sets the setting enable signal to an inactive level with a detection of the falling edge as a trigger;
• and
• a voltage signal converter that generates a voltage level according to a length of a period during which the setting enable signal is at the active level.

A ringing suppression circuit connecting to a transmission line for transmitting a differential signal changed into a high level or a low level as one of binary levels through a pair of signal lines to suppress ringing occurred with a transmission of the differential signal, the ringing suppression circuit comprising:

• a single line switching element, which is driven by a voltage, that is connected between the pair of signal lines;
• a controller that detects a change in a level of the differential signal and turns on the single line switching element to lower an impedance between the pair of signal lines;
• a period detector that detects a length of a suppressing period indicated by a setting signal, which is an input;
• a suppressing period storage that stores the length of the suppressing period which is detected by the period detector;
• and
• a setting signal transmitter that transmits the setting signal to the period detector,
• wherein the pair of signal lines includes a high potential signal line and a low potential signal line,
• wherein the controller turns on the single line switching element for only the suppressing period having the length, which is stored in the suppressing period storage,
• wherein the setting signal transmitter changes a time length, during which a high level or a low level indicated by the setting signal is continued, according to the length of the suppressing period, and transmits the time length,
• wherein the period detector further includes:
• a charger that charges a capacitor according to the time length;
• and
• a plurality of comparators that compare a terminal voltage of the capacitor to different threshold values, and
• wherein the time length is detected according to a number of changes in output signals from the plurality of comparators.

A ringing suppression circuit connecting to a transmission line for transmitting a differential signal changed into a high level or a low level as one of binary levels through a pair of signal lines to suppress ringing occurred with a transmission of the differential signal, the ringing suppression circuit comprising:

• a single line switching element, which is driven by a voltage, that is connected between the pair of signal lines;
• a controller that detects a change in a level of the differential signal and turns on the single line switching element to lower an impedance between the pair of signal lines;
• a period detector that detects a length of a suppressing period indicated by a setting signal, which is an input;
• and
• a suppressing period storage that stores the length of the suppressing period which is detected by the period detector,
• wherein the pair of signal lines includes a high potential signal line and a low potential signal line,
• wherein the controller turns on the single line switching element for only the suppressing period having the length, which is stored in the suppressing period storage,
• wherein the setting signal transmitter that changes an output frequency of an edge, which occurs when the setting signal is changed between binary levels, and
• wherein the period detector detects the output frequency.