posted on 2017-01-10, 05:14authored byGilbert Andrew Matig-a
Electromagnetic
interference (EMI) presents a considerable challenge in wireline
transmitter-receiver designs. In this age when electronic systems are
continuously being miniaturized and multi-functionalized, conventional
electromagnetic interference (EMI) suppression and mitigation solutions become
more impractical as they require more space, additional components and an
increase in the manufacturing costs and delay the development process. Thus,
inherent EMI-self-immune designs become more desirable.
Despite their differential signaling nature, differential
wireline communication front-ends are one of the blocks that are primarily
vulnerable to EMI due to the nonlinear properties of active devices used in
integrated systems. Wireline communication front-end blocks are directly
connected to electrically long transmission lines that act as good receptors of
EMI. Consequently, data transmission errors become predominant as injected EMI
corrupts transmitted data by causing unintended logic state reversals due to
large amplitude excursions brought by the undesired injected signal.
Additionally, an injected EMI causes severe DC shift errors, driving the
front-end blocks out of their operating regions. Hence, EMI corrupts the
integrity of an electronic system when it is not mitigated.
The aim of this research is to eliminate the need for the
costly off-chip EMI suppression and mitigation schemes by designing practical
and efficient integrated EMI solutions that enable integrated wireline
communication front-ends to have self--immunity to EMI. The study focused on
three of the most commonly applied high-speed wireline communication systems –
Low voltage differential signaling (LVDS), current mode logic (CML), and
voltage mode logic (VML). Thus far, EMI self-immune LVDS, CML and VML
transceiver systems have been designed and fabricated using standard UMC 0.18μm CMOS process. The proposed transceivers demonstrated a superior
level of EMI robustness as compared to conventional transceiver structures when
both are subjected to the full spectrum and worst case amplitude of EMI.