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Everyday App Note: How to Keep Your Mixed-Signal Devices Well Grounded

Sam Sattel


Everyday App Note: How to Keep Your Mixed-Signal Devices Well Grounded

Today’s Everyday App Note is flying in from Analog Devices, a leader in the design and manufacturing of analog, mixed-signal, and DSP integrated circuits. It’s time to put away your high-flying theory; this app note is all about getting grounded. In an ideal world, there would be one grounding method to rule them all, but this isn’t reality. In this app note, you’ll learn the best-of strategies for grounding mixed-signal applications.


Who Is This App Note For?

This app note was made specifically for digital or analog designers working on mixed-signal devices. Both specialists have their own unique perspective on a mixed-signal application, so this app note keeps grounding techniques general to apply to both worlds.

Why Should You Read This App Note?

Grounding might be a simple concept, but its actual implementation is incredibly complex and challenging to master. In linear systems, ground serves as both a return path for a power supply current and a reference for signals. Using the wrong grounding strategy to satisfy these two requirements can destroy system performance.

For mixed-signal devices with analog and digital connections, choosing the right grounding strategy becomes even more of a challenge. Whether you’re working with low digital currents or high digital currents, both will require their own preferred grounding approach. This app note covers enough techniques to satisfy both design requirements.

What Problems Does This App Note Solve?

The ugly truth is no universal grounding method guarantees100% performance for any design. Instead of going with a one-size-fits-all approach, this app note covers a variety of grounding strategies that will allow you to take control of problems like:

  • Controlling ground and signal return voltages. Rogue ground and signal return voltages caused by external signal coupling, common currents, or IR drop can hamper performance. With solid ground isolation strategies, you’ll be able to control these parasitic nets.
  • Properly grounding signals in mixed-signal, analog/digital environments. Mixed-signal ICs include both analog and digital pads which makes it confusing to know which grounding technique to use. This app note covers a variety of strategies to meet the needs of mixed-signal devices with both low and high digital currents.
  • Minimizing noise and maximizing range in high-speed environments. Maintaining a high dynamic range and low noise in mixed-signal devices requires a balance of high-speed design strategies. This app note will cover proper signal routing, decoupling, and grounding to help minimize noise and maximize range.



One of the many grounding strategies in this app note – splitting ground planes. (Image source)

It’s time to get grounded. Learn how to keep your signals properly grounded in mixed-signal devices by downloading this application note from Analog Devices now!

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