建立能量收集系統(tǒng)的功率轉(zhuǎn)換級

　　能量收集與傳統(tǒng)系統(tǒng)有很大不同的功率要求。電流和電壓在供給和輸出都能迅速波動。本文從先進的線性器件、線性技術(shù)和德克薩斯儀器等幾項技術(shù)和設(shè)備上進行研究，這些儀器可用于從太陽能、熱能或振動源建立有效的電力系統(tǒng)。

　　來自環(huán)境的能量是自由可用的，但帶著成本；它是低水平的，而且經(jīng)常是可變的。這給能量收集系統(tǒng)的電源管理帶來了一些挑戰(zhàn)。電源管理器必須收集這種能量并將電壓提升到所支持的電子系統(tǒng)所需的水平，同時盡可能少地使用該能量，并提供系統(tǒng)監(jiān)視能力。

　　有幾種不同的電源架構(gòu)，可以為電力系統(tǒng)獲取能量。在“傳統(tǒng)”端，太陽能電池被用來充電電池來存儲能量，然后通過標(biāo)準(zhǔn)的低功耗能量管理芯片來釋放能量，這些芯片具有良好的功率放電曲線。然而，越來越多的系統(tǒng)工程師希望利用可用的能量直接為電子供電。不僅是高度可變的輸入功率，但輸出也經(jīng)常“憔悴”一段時間后一陣電流。這為系統(tǒng)設(shè)計器創(chuàng)建了一組特殊的挑戰(zhàn)。

　　Boosting the voltage is important for the wider adoption of energy-harvesting systems. Some electronics， especially for wearable and ultra-portable systems， are operating at 1.0 V to extend the battery life and simplify the interface to the energy-harvesting power management sub-system. Unfortunately， these are new devices and the majority of designers are working with 1.8 V or even 3.3 V supplies. This also does not take into account sensors and the conditioning electronics such as analog-to-digital converters and amplifiers that may run at higher voltages and still need to be powered by the harvested energy. For some applications， such as smart meters， the rechargeable batteries are even working up to 3.6 V， giving the power management sub-system more of a challenge to address both low and higher voltages.