一种I2C异步低功耗唤醒电路  

A Type of I2C Low-power Asynchronous Wake-up Circuit

作　　者：闫志锋 蒙卡娜 周永存 YAN Zhi-feng;MENG Ka-na;ZHOU Yong-cun(CEC Huada Electronic Design Co.,Ltd.,Beijing Key Laboratory of RFID Chip Test Technology)

机构地区：[1]北京中电华大电子设计有限责任公司,射频识别芯片检测技术北京市重点实验室

出　　处：《中国集成电路》2024年第10期52-55,共4页China lntegrated Circuit

摘　　要：芯片设计中,为了降低芯片功耗,会将芯片划分为多个电源域。在芯片进入低功耗模式时,将不工作的电源域掉电,仅保留必须的电源域带电,达到降低芯片功耗的目的。芯片进入低功耗模式后,主机要和芯片通信,需要先将芯片退出低功耗模式,然后才能正常通信。I2C作为主机和芯片间常用的通信的接口,是一种常用的芯片退低功耗模式唤醒源。常用的I2C唤醒电路中,采用同步电路方式,需要额外的一个高频时钟,用来采样SDA和SCL信号,识别到I2C的起始信号后,唤醒芯片。这种同步唤醒电路,高频采样时钟在低功耗模式期间需要一直工作,增加了唤醒电路的功耗,同时由于只检测START信号,会存在误唤醒的情况。本文介绍了一种I2C异步唤醒电路,该电路不需要高频时钟,也可避免误唤醒的发生。In chip design,in order to reduce power consumption,the chip will be divided into multiple power domains.When the chip enters low-power mode,the inactive power domains will be powered off,and only the necessary power domain is powered on,which can make power consumption as low as possible.Once enters low-power mode,the chip must exit low-power mode before it can communicate normally.I2C,as a commonly used communication interface,is a commonly used chip wake-up source for low-power mode.In a common I2C wake-up circuit,a synchronous circuit is used,which requires an additional high-frequency clock to sample SDA and SCL signals.The chip will be waked up once detecting START symbol.This synchronous wake-up circuit requires the high-frequency sampling clock to operate continuously during low-power mode,which increases the power consumption of the wake-up circuit.At the same time,due to only detecting the START symbol,there may be false wake-up situations.This article introduces an I2C asynchronous wake-up circuit that does not require a high-frequency clock and can avoid the occurrence of false wake-up.

关 键 词：异步 唤醒 接口 低功耗 电源域 电源关断 

分 类 号：TN402[电子电信—微电子学与固体电子学]