V. Finished Project
Research On Design A Low-power Power Management IC
For Thermal Electric Generator (TEG) Application
Overview
Advantages of TEG:
Small size, high power density
Suitable for wearable, IoT and medical devices
Disadvantages of TEG:
Low voltage conversion ratio (≈50mV/1K)
Unstable output voltage
Purpose
To bring TEG to life requires a system that includes a Power management integrated circuit (PMIC). PMIC will do the low voltage amplification of the TEG, ensure a stable output voltage when the voltage of the TEG changes and has the ability to start automatically with low input source.
Further Development
2 new hybrid topologies are proposed: 2-stage boost converter and 3-level boost converter. Both proposed hybrid converter employs an input inductive step-up stage and an output switched-capacitor stage. The first converter, a 2-stage boost converter, has a boost stage connected in series with a switched-capacitor doubler, fully integrated with all control and regulation circuits. The second converter is a three-level boost converter. Both converters are designed in a single prototype chip, fabricated in CMOS-180nm process by TSMC. The PMIC’s self-start operation is verified at a minimum voltage of 50mV. The functionality of both converters are verified to match with simulation results, achieving above 50% efficiency for a wide range of loads. The peak efficiency of the 2-stage boost converter is 65% and, the 3-level boost converter has peak efficiency of 84% in open-loop measurement, 83% in closed-loop simulation.
Related Knowledge
Power electronics: DC-DC converter
Understanding MOSFET’s operation
Software used: Plecs, Matlab, Cadence Virtuoso, Altium Designer