We are working on a board with, among other things, TPS56637 and TPS62913RPUR voltage regulators, a couple of DRV8912-Q1 motor drivers, two ALM2402-Q1 op amps, and an analog subsystem measured by an STM32G474 MCU.
What type of separation of ground planes between the different components is necessary with such a setup? We are not sure if and how we should isolate the various ground planes of these separate components from one another, as the datasheets for each component each illustrate the corresponding component operating in isolation.
One possibility (among many) would be to have the following ground planes used over the board:
**Power_GND** — A separate ground for power components, including the input power protection, the switching regulators mentioned above, and the DRVs.
**Analog_GND** — Individual ground for each analog component directly underneath the component and on one additional layer.
**Signal_GND** — A “general ground�? for all other grounds connecting to all ICs not listed above, the motherboard, and external connectors.
Which of these is necessary to separate, or can they share a single ground? What is the best way to connect each of these grounds to the others? The TPS56637 datasheet recommends connecting at a single point. Is that what we should use for all of these components? Are there other recommendations for keeping signals clean given this set of components?
Please let me know if you need additional information, schematics, or layout drafts for any of this.
