Kyojin Choo

Low-Power and Small Sensors/Actuators Interface

As battery life and production cost are directly linked to the commercial success of IoT and wearables, enabling a family of low-energy sensors/actuators is becoming highly important. Wearables based on low-power sensors/actuators (in milli-to-micro Watts) have successfully debuted as a commercial product. Yet, the requirement for the battery has it conform to a rather strange form factor. Our group believes that enabling a lower power family of sensors/actuators (in nano-Watts), and making them much smaller would enable the artistic design of these everyday things while providing the convenience of modern electronics. 

Charge-Domain Analog/Mixed-Signal Circuits

Analog/mixed-signal circuits traditionally have relied on continuous-time, static-power elements. However, there is a rising opportunity for circuits that focus on "charge" as the main mode of implementing electrical functions. These circuits are efficient as they inherently focus on energy, and provide useful characteristics (such as, noise-efficiency, dynamicity, reusability, scalability) that previous generation analog/mixed-signal circuits could not. Our group is pioneering this newfound design approach to demonstrate highly resource-efficient circuits for applications in energy management, sensor front-end, and communication circuits.

Compact ADC for Array Based Applications

The next wave of circuit applications is enabled by an array of high-performance analogs (and ADCs). These emerging applications include 5G/6G MIMO transceivers, in-memory compute arrays, >100Gbps serial-links, neural probe interfaces, 3D imagers, and many more things to come. Yet, conventional analog circuits greatly discount the effect of size, hence it adversely affects the system cost and robustness when used in an array. I find opportunities in this regard to make them more compact and energy-efficient resorting to novel design approaches (e.g., the charge-injection cell technique for ADCs) that focus on improving performance per area of these analogs. With these techniques, our group intends to further scale down analog circuits by design.