Datasheet

使用指南 Application Guidelines
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Index
EDLC系列設置 Series Configurations of EDLC
單個DRE系列EDLC電壓限制為2.5V，DRL系列EDLC電壓限制為2.7V。因許多應用領域要求高電
壓，EDLC可以設置為串聯以提升工作電壓。確保單一的EDLC電壓不超過其最大的額定工作電壓
是很重要的，否則會導致電解液分解，氣體產生，ESR升高，壽命縮短。
Individual EDLC are limited to 2.5V for DRE series or 2.7V for DRL series. As many applications require higher
voltages, EDLC can be configured in series to increase the working voltage. It is important to ensure that the
individual voltage of any single EDLC does not exceed its maximum recommended working voltage as this will
result in electrolyte decomposition, gas generation, increased ESR and reduced life time.
充電和放電時，在穩態下因容量和漏電流差異，將會產生電容器電壓不平衡現象。在充電時，串聯
電容器將起到電壓分配作用，因此低容值單體將會承受更大的電壓。例如：2個1F電容器進行串聯，
一個電容器容量為+20%，另一個容量為–20%，電壓通過電容器的最差情況為：
Vcap2 = Vsupply x (Ccap1/(Ccap1+Ccap2))
其中Ccap1具備+20%容量。
則Vsupply = 5V，
Vcap2 = 5V x (1.2/(1.2+0.8)) = 3V
Capacitor voltage imbalance is caused, during charge and discharge, by differences in capacitance value and,
in steady state, by differences in capacitor leakage current. During charging, series connected capacitors will
act as a voltage divider so higher capacitance devices will receive greater voltage stress. For example, if two
1F capacitors are connected in series, one at +20% of nominal capacitance, the other at –20%, the worst-case
voltage across the capacitors is given by:
Vcap2 = Vsupply x (Ccap1/(Ccap1+Ccap2))
where Ccap1 has the +20% capacitance.
So for a Vsupply = 5V,
Vcap2 = 5V x (1.2/(1.2+0.8)) = 3V
從上可以看出，為避免超出3V的EDLC浪涌電壓范圍，串聯電容器的容量值應在±20%的公差范圍
內。在選擇上，一個合適的主動電壓平衡電路可用來降低因容值不平衡而產生的電壓不平衡。須注
意到大多數的電壓平衡方法都是取決於具體的應用。
From above, it can be seen that in order to avoid exceeding the EDLC surge voltage rating of 3V , the
capacitance values of series connected parts must fall in a ±20% tolerance range. Alternatively a suitable
active voltage balancing circuit can be employed to reduce voltage imbalance due to capacitance mismatch.
It should be noted that the most appropriate method of voltage balancing depends on the specific application.