Variable battery powered precision analog | Cypress Semiconductor
Variable battery powered precision analog
In the analog kit (http://www.cypress.com/?rID=51577) the designers have separated the voltage supplies and grounds into analog and digital sections, which are then brought back together to common ground near the power supply. This is done to preserve analog performance. The board uses a set of linear regulators to go from an input of 5-12V to either a 3.3V or 5V input to both the analog or digital section of the chip.
I want to design a similar board with a more variable voltage input, including the input of a 3V (~2.8-3.6V) battery. What's the best way of doing this? I'm assuming if I hooked a 3V battery into the analog and digital voltage inputs, the noise from the digital line would affect the analog performance. What steps should be taken to design a reliable power supply with a wide range of voltage inputs (2.8-12V), while still separating the analog and digital inputs?
thanks in advance for any advice,