摘要
To improve the power sequencing performance of the system-on-a-chip（SOC）,a novel embedded soft-start circuit is presented.A seamless soft-start reference voltage is obtained with 7 bits DAC,which can not only restrain the turning point overshoot,but also improve the output accuracy and the poor loading capability,reduce the pin number and save PCB area.The whole DC-DC converter has been fabricated in a 0.35μm CMOS process.The measurement results show that the chip starts up successfully with 250μs soft-start time under conditions of 400 kHz switching frequency,2.5 V DC-DC output and 1.8 V LDO output.Stable operation after soft-start is also shown.
To improve the power sequencing performance of the system-on-a-chip（SOC）,a novel embedded soft-start circuit is presented.A seamless soft-start reference voltage is obtained with 7 bits DAC,which can not only restrain the turning point overshoot,but also improve the output accuracy and the poor loading capability,reduce the pin number and save PCB area.The whole DC-DC converter has been fabricated in a 0.35μm CMOS process.The measurement results show that the chip starts up successfully with 250μs soft-start time under conditions of 400 kHz switching frequency,2.5 V DC-DC output and 1.8 V LDO output.Stable operation after soft-start is also shown.
