Thanks to technological advancements, high-quality healthcare devices, rivalling clinical level of accuracy have found their way into various wearable form factors. Traditionally the main focus has been on improving the power and noise performance of the analog front-end circuits which largely determine the quality of recording. Since most biomedical signals are fairly low frequency, most designs use older technology nodes (like 180nm because of its excellent analog characteristics, mature simulation models and reasonable silicon cost). However as the applications these devices end up in become more advanced, there is a clear need to include ever more digital signal processing and wireless links on the chips. Unfortunately, these older technology nodes are not well suited for digital and RF functionality in a power- and area-efficient manner. While moving towards a more advanced CMOS node, like 40nm or 28nm, will obviously benefit digital and RF, these nodes are not very well suited for power-efficient high-precision analog due to the lower intrinsic gain, higher noise (due to gate leakage) and for analog circuits the area doesn’t scale as easily.
However, there are a number of very advanced technologies on the horizon that could potentially be extremely beneficial for ultra-low-power mixed-signal bio-medical circuit design. Both fully-depleted SOI and FinFET technologies, or even more exotic tunnel FETs, promise a very steep subthreshold slope which could be extremely beneficial for this type of design. In addition, new time-based analog design paradigms could be leveraged in these technologies to actually reduce the area consumption of the analog front-end circuits. While these technologies are currently too expensive to be considered, once they are mainstream, they could allow an order better power consumption at a much smaller die area than traditional bulk CMOS implementations. This would enable a wide range of new applications especially in the field of (minimally invasive) implants and energy-harvesting wearables.
This doctoral research will focus on leveraging the unique technological differentiators of very advanced technology nodes. A heavy focus will be on investigating area and power-efficient design methodologies in these nodes for extremely-low-power biomedical analog front-end circuits. The ultimate goal is to achieve at least a factor lower power and area paving the way for self-sustained minimally invasive implants and wearables.
Electrical engineer with a strong affinity for analog integrated circuit design.
Type of work:
70% analog circuit design, 10% system design, 20% measurements and validation.
Supervisor: Chris Van Hoof
Daily advisor: Nick Van Helleputte
When you apply for this PhD project, mention the following reference code in the imec application form: ref. SE 1704-10.