LVDS is a current looptechnology. Is that a new idea? Well, no. In fact around the time I started work the 20mA current loop was losing ground to RS232-C as a way to interface Teletypes to mainframes. It wasn’t that long ago: Woodstock and the Apollo 11 lunar landing were a whole two years in the past by then! The idea of a current loop is simple: The transmitter injects a current that passes through a resistor and because, by Ohm’s Law, V=IR, a voltage is developed across it.
Why Simulate PCBs at All? On-and off-piste Gigabit Signaling, Simulation and Modeling
This may seem a strange question for someone who’s made their living out of signal integrity for so long, but things have changed. There was a period in the 80s and 90s that I call the SI Deficit: the period when signal integrity issues took engineers by surprise and my specialty was even called “Black Magic”. The design landscape has changed radically since then – the main reason for this being standardization…
