Myungjoon Choi

Contact Information:

2435 EECS
1301 Beal Avenue
Ann Arbor, MI 48109-2122
myungjun@umich.edu

 

 

Research Interest:

low-power circuit design, millimeter-scale sensor nodes, circuit robustness over temperature variations

Current Research:

1. A 23pW 780ppm/C Resistor-less Current Reference Using Subthreshold MOSFETs 

This research proposes a MOSFET-only, 20pA, 780ppm/ºC current reference that consumes 23pW. The ultra-low power circuit exploits subthreshold-biased MOSFETs and a complementary-to-absolute temperature (CTAT) gate voltage to compensate for temperature dependency. The design shows low supply voltage sensitivity of 0.58%/V and a load sensitivity of 0.25%/V. 

2. A Wide Input Range Resistive Sensor Interface Circuit with Sub-Ranging 

A wide input range resistive sensor interface circuit is widely used in chemical, gas and bio applications. This work suggests a novel way of sub ranging which helps reducing power consumption and maintaining accuracy over wide range. 

3. Robustness of the subthreshold leakage-based timer upon temperature variation. 

The timer of simple structure can be implemented by a subthreshold leakage-based topology. However, it suffers from temperature variations as the leakage exponentially depends on the temperature. Maintaining the functionality and furthermore, reducing output frequency variation on varying temperature need to be researched.