The invention relates to a circuit for improving energy transmission efficiency of a non-
contact type IC (
integrated circuit) card, belonging to the technical field of energy transmission circuits of high-current
passive systems. The circuit is characterized by sequentially comprising a matching circuit, a
rectifier circuit, a
voltage-stabilizing and amplitude-limiting circuit, an
energy storage circuit, a current monitoring circuit and a switch
control circuit, wherein the matching circuit comprises a plurality of capacitors and a switch, and is used for obtaining
best matching; the
rectifier circuit comprises a plurality of MOS (
metal oxide semiconductor) transistors and is used for converting
alternating current voltage to
direct current voltage; the voltage-stabilizing and amplitude-limiting circuit comprises a plurality of voltage-stabilizing units and amplitude-limiting units and is used for stabilizing the
direct current voltage output by the last stage; the
energy storage circuit comprises an
energy storage capacitor and is used for storing energy when the
field strength is reduced; and the switch
control circuit comprises a current
reproduction tube and a
comparator and is used for controlling a switch in the matching circuit. The circuit disclosed by the invention can improve the energy transmission efficiency by automatically adjusting the matching circuit under the situations of low
field strength and large load, can meet the requirements of the non-
contact type IC card with a larger load, and can be applied to power supply for all modules in smart IC cards such as a financial IC card and the like.