FRAM芯片擴(kuò)展在低功率應(yīng)用中的耐力

　　雖然EEPROM和FLASH通常被用于非易失性存儲(chǔ)器的首選（NVM）在大多數(shù)應(yīng)用中，鐵電存儲(chǔ)器（FRAM）為能量收集應(yīng)用如無(wú)線(xiàn)傳感器節(jié)點(diǎn)，智能電表的許多低功耗設(shè)計(jì)獨(dú)特的優(yōu)勢(shì)，和其他數(shù)據(jù)采集設(shè)計(jì)。其擴(kuò)展的讀寫(xiě)周期和數(shù)據(jù)保留時(shí)間，F(xiàn)RAM技術(shù)可以幫助設(shè)計(jì)人員滿(mǎn)足要求使用十年，F(xiàn)RAM芯片低功耗運(yùn)行框架基于MCU的NVM制造商包括Cypress半導(dǎo)體、富士通半導(dǎo)體、羅姆半導(dǎo)體、德克薩斯文書(shū)。

　　傳統(tǒng)的NVMs，如FLASH和EEPROM，在浮柵中的電荷泵，需要提高電壓的需要迫使運(yùn)營(yíng)商通過(guò)柵氧化層的水平電荷載體的形式存儲(chǔ)數(shù)據(jù)。其結(jié)果是，隨著長(zhǎng)期寫(xiě)入延遲和高功率消耗在這些設(shè)備中固有的，其高電壓寫(xiě)操作可以最終磨損細(xì)胞-有時(shí)在只有10000個(gè)寫(xiě)周期。

　　FRAM advantages

　　In contrast， Ferroelectric RAM （FRAM） stores data by means of the polarization of the ferroelectric material lead zirconate titanate， or PZT （Pb （ZrTi）O3）， which is placed as a film between two electrodes similar to the structure of a capacitor. As with a DRAM， each bit in a FRAM array is read and written individually， but while DRAM uses a transistor and capacitor to store the bit， FRAM uses a dipole shift in the crystalline structure for the corresponding bit caused by application of an electric field across the electrodes （Figure 1）。 Because this polarization remains after the electric field is removed， the FRAM data persists indefinitely even without available power – a vital capability for designs powered by uncertain ambient sources.