Research And Design Of Low Voltage Start-up And DC-DC Converter Chip For Energy Collection

With the development of microelectronics technology,the power consumption of some electronic systems has been reduced to microwatt level.It is possible to collect microenergy widely existing in the environment to supply power for low-power electronic systems.It has been applied in automotive industry,intelligent buildings,Internet of Things applications,medical treatment and animal tracking protection.In some cases where traditional batteries are not suitable for use,there is an urgent need for energy collection systems.How to achieve energy collection,rectification and boost,and provide energy for electronic systems has become a research hotspot.In this paper,TSMC 0.18 m process is used to study the low-voltage start-up and DC-DC conversion technology applied in energy collection system.This paper introduces the common structure of energy collection system and inductance system structure,introduces the common structure of self-starting circuit,designs two kinds of self-starting circuit which can realize energy fusion,and uses threshold voltage reduction technology to improve performance,designs low voltage DC self-starting circuit to ensure the stability of system start-up,and introduces the system maximum power control method.Aiming at the problem of efficiency reduction caused by traditional voltage stabilization strategy,the overall control strategy of the system is proposed and completed,which is more practical.A multi-energy fusion boost and self-start circuit is designed.The boost and self-start functions are fused with two kinds of energy,which improves the traditional self-start circuit's strict requirement for a single energy and can still start when the single energy is low.The simulation results show that when VDC=200 mV,RF=-15 dBm and output voltage 1.5 V reduce the peak value of RF signal voltage to 225 mV;when VDC=0,the output voltage of the circuit is 1.4 V,when RF=-14 dBm,the peak value of RF signal voltage is required to be 250 mV;and the peak value of input voltage of RF is reduced by about 70% compared with the same period of last year.A DC low-voltage self-starting circuit is designed,which improves the difficulty of traditional self-starting structure when the clock signal is low.Through two-stage voltage doubling circuit working in sub-threshold region,the minimum voltage can be raised to more than 1V at 80 mV,and the self-starting function can be realized with ring oscillator and charge pump circuit.The simulation results show that the proposed DC start-up mode can realize self-start at 80 mV.A practical control scheme for energy collection system is proposed.The inductor boost is maintained at the maximum power and the load demand is provided.The excess energy is stored in the off-chip storage capacitor.When the energy is insufficient,the off-chip capacitor provides the energy demand for the system.This control scheme avoids the problem of reducing the energy collection efficiency when the traditional control scheme stabilizes the output voltage.The system stability and stabilized output are guaranteed by using over-voltage conduction circuit and low-power stabilized voltage circuit.The simulation results show that when the input voltage is 100 mV and the load resistance is 2 M,the scheme can maintain the output voltage at 1.8 V about 20 ms when the input voltage is zero,which greatly improves the practicability of the energy collection system.