Design Of Linear Regulator With Source And Sink Current Capability

Since the 21 st century,the rapid development of electronic products,especially consumer electronic products such as mobile phones,laptops and other portable electronic devices have become an indispensable part of People’s Daily life.The power management chip is responsible for the conversion,distribution,monitoring and other power management functions and responsibilities in the electronic equipment system.Power management chip is indispensable for electronic system,its performance has a direct impact on the normal work of load client.Double Data Rate（DDR）is a kind of memory unit that can read and write simultaneously in one clock cycle.The terminal voltage regulator of DDR should have the capacity of pull-current to realize the double-rate storage capacity of Data,and the load of pull-current should be more than 2A.The voltage regulator designed in this paper is a terminal voltage regulator with sourcing and sinking current capability,which can supply power to one or more DDR memory modules.In addition to the error amplifier and power circuit which are capable of driving the sourcing and sinking current,the designed Voltage regulator chip also adds Under Voltage Lock Out（UVLO）module,Over Temperature Protection（OTP）circuit,Over Current Limiting（OCL）circuit,Electrostatic Discharge（ESD）module.Including innovation put forward a kind of overvoltage monitoring current limiting protection design,namely under the effect of different output voltage through bilateral overvoltage module give transconductance amplifier feedback,by sampling resistor sampling current ACTS on the error amplifier,makes the error amplifier to exert different levels of power tube control,so as to realize overvoltage detection limit the flow.In this way,the output voltage is stable to a certain extent,and the whole circuit will not be directly closed due to excessive load current,effectively limiting the upper limit of load current and protecting the circuit.Based on HGBCD350 GE technology,Cadence Virtuoso tool is used to design and simulate the voltage regulator circuit.Terminal voltage regulator operating temperature range is-55℃ ～ 125℃,ESD is 2000 V,working voltage is 2.375 ～ 3.5V,output voltage is 0.9V.Under the output voltage accuracy of 35 m V,it can achieve more than 2A sourcing current load capacity and more than 3A sinking current load capacity.Under current limiting protection,the sourcing current is limited to 3.6a when the output voltage is 0.81V;When the output voltage is 0.99 V,the sinking current is limited to 4.85 A.PSRR is greater than 60 d B@100k Hz.The simulation results show that the main performance parameters meet the design requirements.