There’s a further cool thing you can do with a spreadsheet that most SPICEs can’t. That’s to use the spreadsheet ‘solver’ functionality to adjust component values in the search for a better-fitting circuit – or even to find a set of component values for a circuit you can’t otherwise design.
You now need to adjust component values to achieve some system goal, such as predefined frequency response or time behaviour, and there’s no closed method for working out those values.
The required selectivity of a customer design implied four-pole filters with about 10% bandwidth (passband width about 10% of the centre frequency). There was a catch---a tight power budget
Now, our customer doesn’t want to buy big, expensive, high quality capacitors to build an active filter with this response. So, having established the principle of optimizing in the analogue domain, let’s look at whether need to make any changes in order to use it to create a digital filter – which we’ll be able to implement on the Cypress PSoC 3