使用小片上电容的VCCS补偿的LDO

A stable LDO using VCCS(voltage control current source) is presented.The LDO is designed and implemented on GF 2P4 M 0.35 m CMOS technology.Compared with a previous compensation scheme,VCCS can implement a real stable LDO with a small on-chip capacitor of 1 p F,whose stability is not affected by the variable ESR(equivalent series resistance) of the output capacitor.The unit gain frequency of the LDO loop can achieve 1.5 MHz,improving the transient response.The PSR of the LDO is larger than 45 d B within 0–40 k Hz.The static current of the LDO at heavy load of 100 m A is 57 A and the dropout voltage of the LDO is 150 m V.Experimental results show that a setting time of 10 s is achieved,and the variation of output voltage is smaller than 35 m V for a 100 m A load step in transient response of the LDO.     

一种快速PWM调光,双路控制,无采样电阻的升压LED驱动器

A boost LED driver featuring a high PWM dimming ratio and optimized efficiency is presented.This LED driver,which has a low dropout voltage and is able to drive 3-7 LEDs in series with constant output current and fast PWM dimming,provides an alternative technique for brightness adjustment.A dual-path control scheme with automatic switching and state maintenance is proposed.Meanwhile,a cascode current mirror structure is applied with the output transistor multiplexed as an LED PWM dimming transistor.Implemented in 0.5μm 25 V BCD process,the measurement results show that a voltage conversion range of 5 V input to 6-24 V output with constant output current is obtained.With automatically switching dual-path control and an optimized current mirror,the response time during PWM dimming is reduced to as low as 240 ns and the efficiency keeps above 89%over a wide PWM dimming ratio @ 250 mA output current.     

A 1500 mA,10 MHz on-time controlled buck converter with ripple compensation and efficiency optimization

正A 1500 mA,10 MHz self-adaptive on-time(SOT) controlled buck DC-DC converter is presented.Both a low-cost ripple compensation scheme(RCS) and a self-adaptive on-time generator(SAOTG) are proposed to solve the system stability and frequency variation problem.Meanwhile a self-adaptive power transistor sizing(SAPTS) technique is used to optimize the efficiency especially with a heavy load.The circuit is implemented in a 2P4M 0.35μm CMOS process.A small external inductor of 0.47μH and a capacitor of 4.7μF are used to lower the cost of the converter and keep the output ripple to less than 10 mV.The measurement results show that the overshoot of the load transient response is 8 mV @ 200 mA step and the dynamic voltage scaling(DVS) performance is a rise of 16μs/V and a fall of 20μs/V.With a SAPTS technique and PFM control,the efficiency is maintained at more than 81%for a load range of 20 to 1500 mA and the peak efficiency reaches 88.43%.     

一种带双重纹波补偿的10MHZ导通时间纹波控制降压型转化器

A 10 MHz ripple-based on-time controlled buck converter is presented.A novel low-cost dual ripple compensation,which consists of coupling capacitor compensation and passive equivalent series resistance compensation, is proposed to achieve a fast load transient response and robust stability simultaneously.Implemented in a 2P4M 0.35μm CMOS process,the converter achieves fix-frequency output with a ripple of below 10 mV and an overshoot of 10 mV at 400 mA step load transient response.With width optimization of the power transistors in an ultra-heavy load and PFM control in a light load,the efficiency stays at over 83%for a load range from 20 mA to 1.5 A and the peak efficiency reaches 90.16%.     

一种带纹波补偿和效率优化的1500mA，10MHz导通时间控制降压型转化器

本文叙述了一种由自适应导通时间控制的1500mA,10MHz降压型转换器。文中提出的低成本纹波补偿技术和自适应导通时间产生电路分别解决了系统稳定性和频率变化问题。同时,一种自适应功率管分段技术被用于优化整体效率,特别是重负载下的效率。该转换器电路采用2P4M 0.35微米CMOS工艺流片验证。外部使用0.47μH电感和4.7μF电容以减小转换器成本,并保证输出纹波小于10mV。测试结果显示,负载跳变时的过冲为8mV每200mA,DVS性能为16μs/V上升和20μs/V下降。由于自适应功率管分段技术和PFM作用,转换器在20mA到1500mA范围内的整体效率保持在81%以上,同时峰值效率可达88.43%。