摘要
利用逐次逼近型A/D转换器及数字逻辑电路,设计了一种用于RTC的温度自适应晶振频率修调电路。该修调系统依据芯片所用晶体的温度特性曲线,对标称频率为32.768kHz的晶体进行随温度变化的频率调整。该电路采用CSMC0.5μm CMOS工艺,可对晶振频率进行-192.150～+192.150(×10-6)的修正,频率修调范围为±6.396Hz;在-40℃～85℃范围内,时钟精度可达到±1.525×10-6;在3.3V电压下,静态电流为13.5μA。
An integrated temperature-adaptive frequency trimming circuit for RTC was designed using an 8-hit SAR A/D converter and a digital logic block. Depending on temperature characteristics of different crystals, the system could trim frequencies for crystal with a nominal frequency of 32. 768 kHz as it varies with temperature. Simulation based on CSMC＇s 0. 5μm CMOS mixed-signal model showed that the circuit could make frequency trimming from -192. 150×10^-6 to＋192. 150 × 10^-6 , with a accuracy of ± 1. 525 ×10^-6 in the temperature range from -40 ℃ to ＋85℃.
出处
《微电子学》
CAS
CSCD
北大核心
2009年第3期320-323,共4页
Microelectronics
