By Peter Clarke, eeNews Analog (November 25, 2021)
Tuomas Hollman became CEO of Finnish near-threshold voltage pioneer Minima Processor Oy in May 2019 and since then he has been preparing the startup for growth.
We asked Hollman to tell us how the company would be using its recently announced European funding (see Europe invests €227m directly in tech startups) and he shared his opinion on why circuit design has to change. He said: "Static timing sign-off is over."
Minima Processors was founded in 2016 following a resurgence of interest in sub- and near-threshold voltage operation of circuits. Transistor power consumption is related to the square of the voltage of operation so reducing the voltage produces a square-law benefit. The disadvantage is that signal transitions are slowed and therefore in clocked digital logic the maximum clock frequency has to be reduced. It's a trade-off but one that often produces an overall benefit and this has been exploited in specialist circuits, such as in electronic watch circuits, since the 1970s.
However, the devil is in the detail and in the fabless-foundry world transistor and standard cell models are usually only characterized at well above threshold voltage. This makes the route to market for fabless chip companies more complex in terms of risk than conventional design using standard cells and IP cores, as given.