An internal-resistance-adaptive MPPT circuit for energy harvesting.

This paper presents a built-in input matching technique capable of handling a wide variation of multi-array thermoelectric generator (TEG) impedances, from 5 Ω to 2.7 K Ω , which is called internal-resistance-adaptive (IRA) maximum power point tracking (MPPT) technique. The IRA circuit and delay synthesis circuit in the IRA-MPPT can track the dynamic changes of the internal resistance of the energy source in real time, and transmit the optimized switching time to the switching transistor to maximize the end-to-end efficiency (η E–E). The circuit is designed and simulated using 0. 18 μ m technology. An improvement of 23.23%@(R S = 2.7 K Ω , V S = 0.6 V) in η E–E is achieved with the proposed technique. Furthermore, the simulation results show that a higher than 46%@(R S = 5 Ω , V S = 0.03 V) efficiency can be achieved over an input resistance (R S) range of 5 Ω –2.7 K Ω and an power range of 12 μ W–50 mW with a 95.52%@(R S = 100 Ω , V S = 1 V) peak efficiency. [ABSTRACT FROM AUTHOR]