一种用于数字陀螺系统中LDO设计

发布时间：2018-03-04 13:42

  本文选题：低压差稳压器　切入点：误差放大器　出处：《哈尔滨工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着近几年陀螺传感器的广泛应用,市场对陀螺系统提出了更高的指标要求,市场需求促进了国内外对陀螺系统的研究。电源管理系统作为陀螺系统中的关键模块也成为一大热点。现电源管理系统主要由低压差线性稳压器(Low-Dropout linear regulator)和开关电源组合而成。本文主要研究了应用在数字陀螺系统中的无片外电容的低压差线性稳压器。这将有利于陀螺芯片的集成化,使其更广泛应用在电子产品中,满足市场需求。在详细介绍LDO基本工作原理之后,依次分析了LDO的各个关键指标。随后根据LDO系统指标的要求,开始对LDO中的带隙基准电路,误差放大器等模块进行设计。设计时为了提高系统的温度系数,对带隙基准源进行了高阶温度补偿,用不同温度系数的电阻来补偿其温度系数的高阶项。其次考虑到LDO负载变化快,应用了快速瞬态响应补偿回路,来改善系统的瞬态响应。出于对系统稳定性的考虑,在瞬态补偿电路中增加了补偿电容,使此补偿电路具有类密勒效应。然后建立系统的等效小信号模型,分析系统稳定性。因为负载电流大,为了保证LDO能够输出足够大的电流和实现低压差,采用了PMOS做功率管。完成各单元电路设计,对整体LDO电路仿真验证性能,满足指标要求后绘制电路版图。本文设计的低压差线性稳压器采用0.35μm CMOS工艺,并在Cadence中完成了具体电路设计和版图设计。仿真结果表明了LDO系统稳定输出0-30mA电流。在室温条件下测得LDO的线性调整率是37.1μ/V,负载调整率是1.2μV/mA;-40°C到85°C范围内温度系数为4.1ppm/°C,最大过冲电压为103mV;系统开环增益134dB,相位裕度大于60?,电源抑制比在低频时为82dB。综上,本论文设计的LDO满足系统应用要求。
[Abstract]:With the wide application of gyroscope sensors in recent years, the market has put forward higher requirements for gyroscope system. The market demand has promoted the research of gyroscope system at home and abroad. As the key module of gyroscope system, power management system has become a hot spot. At present, the power management system is mainly composed of Low-Dropout linear regulator and switch electricity. This paper mainly studies the low-voltage differential linear voltage regulator without off-chip capacitance in digital gyroscope system, which will be beneficial to the integration of gyro chip. After introducing the basic working principle of LDO in detail, the key indexes of LDO are analyzed in turn. Then, according to the requirements of LDO system, the bandgap reference circuit in LDO is started. In order to improve the temperature coefficient of the system, the high-order temperature compensation of the band-gap reference source is carried out in order to improve the temperature coefficient of the system. The resistance of different temperature coefficients is used to compensate the higher order term of the temperature coefficient. Secondly, considering the fast change of LDO load, the fast transient response compensation loop is applied to improve the transient response of the system. The compensation capacitor is added to the transient compensation circuit to make the compensation circuit have similar Miller effect. Then the equivalent small signal model of the system is established to analyze the stability of the system. In order to ensure that LDO can output large enough current and realize low voltage difference, PMOS is used as power transistor. The circuit design of each unit is completed, and the performance of the whole LDO circuit is verified by simulation. The low voltage difference linear regulator designed in this paper adopts 0.35 渭 m CMOS process. The simulation results show that the LDO system outputs 0-30mA current stably. At room temperature, the linear adjustment rate of LDO is 37.1 渭 / V, and the load adjustment rate is 1.2 渭 V / mA1-40 掳C to 85 掳C. The maximum overshoot voltage is 103 MV, the open loop gain of the system is 134 dB, the phase margin is greater than 60? The PSRR is 82 dB at low frequency. In summary, the LDO designed in this paper meets the requirements of system application.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM44
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本文编号：1565875