Research And Design Of A Low Linear Regulator In 0.35?m BCD Process

With the proliferation of battery-powered equipment,such as smart phone,mobile internet device(MID)and handheld game console,having increasingly become electronic products with that people will go out with,their endurance capacity and volume are increasingly concerned about with market.The power IC,as the energy conversion link,is the other factor constrains electronic products development besides lithium battery.The LDO(Low Dropout Linear Regulator)is the best choice of proliferation of batterypowered equipment be cause of its low cost,low noise,high accuracy and small area.Therefore,it's important for studying a more efficient,lower noise and higher precision LDO.According to the hotspot of LDO,in the paper a high performance LDO is designed based on 0.35?m BCD process.It has a 5.2V-16 V input range,5V output and-55?-125? operating temperature.The LDO uses NMOS as the pass element to enhance low frequency PSRR and reduce the dropout voltage,while an offset capacity and servo amplifier are introduced to impove static consumption and high frequency noise from charge pump.Additionally,there is a charge release circuit in the enable module for fast shutdown.In order to reduce consumption and area,the reference circuit utilize the amp's offset voltage to realize reference voltage generation.Its TC is 12.5ppm/? in typical conditions.A gate drive circuit for a switched Dickson charge pump is designed to improve charge pump efficiency.Finally,we also introduce thermal protection,overcurrent protection and ERROR module to ensure LDO working properly.The simulation and layout is worked by software Cadence.Now the LDO has been taped out.The DC test results show that dropout voltage is 122 mV with 25? and typical load(200mA),line regulator is 0.42% with 5V-10 V input voltage and load regulator is 0.32% with 0m A-200 mA load current.The transient test results show that overshoot and undershoot is 68 mV and 102 mV respectively in 0-200 mA load transition,140 mV and 196 mV respectively in 0-400 mA load transition.