When designing a solution that can be configured for many different measurements, a thought that usually comes to mind is, how can this specific block be reused, does it make sense, and what are the things that need to be considered.

Let's for a moment take a look at the AD8233 from Analog Devices, this is a 50uA 3.4mm2 low noise heart rate monitor that is targeted specifically for the wearable space, where power size and performance are key requirements, and the AD8233 ticks every box pretty well.

The AD8233 might be pitched as an ECG device and it does play this function very well, but if we take a closer look at the block diagram of the AD8233, then quickly realize that the architecture employed is essentially an instrumentation amplifier, thus this device could easily be reused where low power small size and good performance is needed. If someone was looking to design a battery-powered VSM device where ECG, pressure, and temperature were required, then this device could be used for all these measurement modalities with some minor tweaks.


Figure 1. AD8233 Integrated Signal Conditioning Block 

If we broaden the lens and look at the vast number of low applications where we could easily apply this same thinking, then the key benefits of using the AD8233 as a platform part really start to resonate. Take a look at this excellent article on Analog Dialogue 'Flexible ECG Front-End IC Serves Ultralow Power IoT Edge Node Signal Processing Design', this article discusses the key benefits of the AD8233 beyond ECG measurements, when features such as ultra-active low power, tiny package, and the ability to shutdown are the main requirements for the end application design.