Low frequency reduced passive equalizer
AssigneeQuanta Computer Inc.
InventorCheng-Hsien Lee
Life of this patent
Estimating the term…
Abstract
A differential trace structure reducing the magnitude of low frequency attenuation is disclosed. The trace structure is formed on a printed circuit board. A pair of differential traces connects a signal receiver and a signal transmitter. A passive equalizer has a first shunt coupled to one of the pair of differential traces; and a second shunt coupled to the other one of the pair of differential traces. The passive equalizer has an inductor and a resistor coupled in series to the shunts. For low frequency signals, the passive equalizer behaves as a shunt resistance to the pair of differential traces.
Claims10
A high speed circuit, comprising:
- a printed circuit board having a top surface and a bottom surface;
- a signal transmitter on the printed circuit board;
- a signal receiver on the printed circuit board;
- a pair of differential traces connecting the signal receiver and the signal transmitter;
- and
- a passive equalizer connected to the pair of differential traces, the passive equalizer interconnecting the signal transmitter and the signal receiver, the passive equalizer being neither a part of the signal transmitter, nor a part of the signal receiver, the passive equalizer behaving as a shunt resistance between the pair of differential traces for low frequency signals, wherein the passive equalizer comprises an inductor coupled between the pair of differential traces and positioned on the top surface or the bottom surface.
A passive equalizer to reduce the attenuation of low frequency signals on a differential trace pair comprising a first trace and a second trace on a printed circuit board having a top surface and a bottom surface, the passive equalizer consisting of:
- a first shunt having a first end and a second end, the first end of the first shunt coupled to the first trace of the pair of differential traces on the printed circuit board;
- a second shunt having a first end and a second end, the first end of the second shunt coupled to the second trace of the pair of differential traces on the printed circuit board;
- one or more inductors coupled between the second end of the first shunt and the second end of the second shunt, the one or more inductors positioned on the top surface or the bottom surface of the printed circuit board;
- and
- one or more resistors coupled in series with the one or more inductors between the second end of the first shunt and the second end of the second shunt, wherein the one or more inductors and the one or more resistors behave as a shunt resistance to the pair of differential traces for low frequency signals.
Dependencies are inferred from the claim text.