Issue link: https://resources.mouser.com/i/1505196
mouser.com/vishay / 7 The goal of more than 10 years of usability, as was aspired to years ago in the IoT world, can only be achieved if all components used are optimized in a nano-ampere design and operate efficiently with minimum losses. An ultra- low-reverse-voltage—such as Vishay's VSKY02300603 with 1μA reverse operation—can prevent the discharge of ENYCAP capacitors during periods of darkness. However, only active, back-to-back isolation using p-channel MOSFETs—such as the Si8819EDB in the MICRO FOOT ® (BGA) package or the SiUD403ED in the PowerPAK ® 0806—achieves typical reverse leakage currents of 10nA. V-Harvester Reference Board Vishay designed a V-Harvester board that meets all of the requirements for an ultra-long-lasting IoT sensor. One key aspect is the voltage sensing of charge and control, which is often performed by high-ohmic voltage dividers that consume less than 0.1μA of power while offering tight tolerances. Often, thick film technology can't provide the required tolerances and ohmic values. However, the divider implemented in Vishay's V-Harvester board is a thick film resistor in the 0402 case size from the RCWP series, which offers 1% tolerances and on-resistance of 20MW for industrial and other high reliability applications. High ohmic voltage divider Thick film 0402 1% ≥ 20MΩ RCWP040220M0FKEC "Even the best disconnect switch doesn't provide a benefit if the self-discharge of the storage capacitor is too high." Even the best disconnect switch doesn't provide a benefit if the self-discharge of the storage capacitor is too high. One particular focus in the development of ENYCAP technology was to reduce the self-discharge to such an extent that even after 12 months, more than 60% of the capacitor's charge is still available. This allows ENYCAP devices to be used over a long period of time with only a little harvested energy. Conversely, they can provide enough energy to the sensor and the radio module if both circuits must measure or transmit often for applications like radio messages in the 5G or ISM radio alarm band. And many industrial IoT, M2M, intralogistics, and other network systems in industrial applications are designed precisely for this use. Figure 1: V-Harvester reference board. (Source: Vishay)