一种用于模数转换器时钟管理电路的电荷泵

A Charge Pump for Clock Management Circuit of Analog-to-Digital Converters

采用0.13μm CMOS工艺,设计了一种用于模数转换器时钟电路的电荷泵。在共源共栅充/放电流源与其偏置电路之间增加传输门,有效地抑制了电荷泵关闭时产生的漏电流。同时,采用电流源提升技术,有效地提高了电荷泵充/放电电流支路的阻抗,抑制了沟道长度调制效应的影响,提高了电荷泵的电流匹配性。仿真结果表明,在1.2 V电源电压、20μA输出电流的条件下,输出电压的变化范围为0.13~0.93 V时,该电荷泵的充/放电电流失配低于1%。

A charge pump for clock management circuit of analog-to-digital converters(ADC)was designed in a 0.13μm CMOS process.By adding transmission gates between the cascode charge-discharge current source and its bias circuit,the generation of leakage current was effectively suppressed when the charge pump was turned off.By adopting the current source enhanced technique,the impedance of charge-discharge current branch of charge pump was effectively improved,and the influence of channel-length modulation effect was suppressed,so the current matching performance of charge pump was effectively improved.Simulation results showed that the charge-discharge current mismatch was less than 1%with the output voltage varied from 0.13 V to 0.93 V under the condition of 1.2 V power supply voltage and 20μA output current.