Design Of Power Manage Unit Of Passive UHF RFID Tag Chip

With the implementation of the national Internet of things (IOT) strategy, smart car, smart home and other new concepts have been proposed one after another. As a kind of developing trend, the IOT gives us great imagination space. The development of the IOT can't leave the Radio Frequency Identification technology (Radio Frequency Identification, RFID)-a technology that makes RF signal space coupling achieving non-contact information transmission. Passive UHF RFID tag is to use this technique to perform its characteristics, such as long identification distance, high accuracy, and identifying multiple targets, which are popular with the market. Acquisition and conversion of energy in Passive UHF RFID tag chip is critical, it is the most main factor that affect the tag sensitivity. So the tag chip power management modules are particularly important.This article explains the principle how the passive tag chip getting energy on system level, and all of the passive UHF RFID tag chip power management modules are described in detail, which including the voltage limiting circuit, bandgap reference circuit, and a voltage switching circuit. For studying the four circuit modules, the research idea starts with the basic working principle, and then extends out the key specifications of some major or design points, also shows the design and simulation analysis. Voltage limiting circuit is relatively simple. However, because of considering more index relatively, the design of bandgap reference circuit and LDO are relatively complicated. For this condition, this article analyze the three kinds of bandgap reference circuits that commonly used, including the type of low voltage low power consumption, high PSRR and higher order temperature compensation. However,coming up with a bandgap reference circuit used in the project, the power consumption of which only 0.55 uW, and can work at the voltage as low as 0.96V,also the temperature coefficient is only 84 ppm/?. Moreover, the starting circuit of the bandgap reference circuit also mades a very detailed explanation. For the LDO circuit, this paper mainly mades a detailed analysis of the loop way of phase compensation, and respectively analyzes the advantages and disadvantages of the miller compensation, zero-pole compensation, ESR compensation and phase-advanced compensation. Finally, the article comes up with a LDO circuit, and carries on the detailed simulation analysis of the key specifications. For voltage switching module which is designed based on the LDO circuit, transient characteristic is analyzed only.In the end, the article points out some commonly used skills in the process of designing layout, and draws the layout of the whole passive UHF RFID tag chip and its power management modules. The Chip fabricated in TSMC 0.18 um 1p5m process finally, then we made the test about its sensitivity and some specifications about its power management modules.