A Design Of LDO Applied To The OTP Module Of TPMS-Chip

Tire pressure monitoring system(TPMS) is a highly sensitive micro-sensors which is installed in the car tire. It can effectively monitor the temperature and pressure of the tire,and it provides an effective defense measures for the safety of automobiles. Before the TPMS system chip works, it needs to be initialized parameters. This initialization process is achieved by OTP which is a part of TPMS. The purpose of this paper is to design and implement a low dropout regulator(LDO) which is used as a power supply for the OTP,and it has broad market prospects.First of all, we analyse application requirements of OTP, system architecture and theory of LDO. On this basis, we propose a scheme with simple structure and low power consumption. Then, we finish the design of bandgap reference, error amplifier and bias circuit. The scheme uses a symmetry error amplifier wide bandwidth and good stability.Not only that, this scheme uses Miller compensation to optimize the stability of the LDO.According to the requirements of TPMS-Chip, this LDO has the function of dormancy. When the OTP finishes the initialization process, the LDO cuts off the power of the OTP. So we achieve the goal of low power consumption design.This LDO could transform the supply voltage of lithium battery(2.0 V to 3.6 V) into a stable voltage(1.8 V). This design applies SMIC 0.18 um CMOS manufacturing process,we simulate the DC characteristics, AC characteristics, transient characteristics and temperature characteristics of this LDO. Taking TT process corner as a example, the line regulation is 1.4mV/V, the load regulation is 2.14uV/mA, the power supply rejection ratio is-61.6dB, the phase margin is 78.3deg. This LDO reaches the expected performance indicators,and meets the power requirement of the OTP.