E-Peas is Helping Enable Epishine’s New, Novel and Thin Indoor Energy Harvesting SolutionApril 03, 2021 by Nicholas St. John
The world is getting smarter, and the devices that enable that intelligence are getting smaller. For this to continue, especially in indoor environments, electronic devices need to operate at very low power. Companies Epishine and e-peas have found a solution to push past this bottleneck.
E-peas, a company that develops ultra-low power semiconductor technology, has partnered with Epishine, a manufacturer of organic solar technology, to create an indoor-optimized energy harvesting solution via their evaluation kit, allowing devices to “cut the cord” and no longer depend on external charging as seen in an e-peas press release.
The solution is centered around the novel e-peas developed energy harvesting power management integrated circuit (PMIC), the AEM10941. This IC provides intelligent charging, with an integrated boost regulator and two low dropout voltage regulators (LDOs). The AEM10941 is connected to 6 Light Energy Harvesting (LEH) modules from Epishine, photocells that are printed onto recyclable plastic, making it highly cost-effective while being able to provide ample power to the PMIC in dim indoor lighting, down to 50 lux (where normal indoor lighting is 8 times greater at 400). This low-light operating capability is due to the AEM10941’s ability to start up, even from the worst-case scenario of a cold start and a completely drained charging source, at an input voltage and current of 380mV and 7.9uA respectively.
In total, the evaluation kit requires minimal external components due to the highly integrated while yet compact AEM10941, at only 81mm x 71.5mm x 3.8mm. The PMIC charges a CAP-XX 300mF, GA230 supercapacitor to an adjustable voltage between 1.8V and 3.3V with 100mV steps. The CAP-XX when discharged can provide up to 80mA of current, enough to power a radio transceiver for wireless applications and one can also connect a backup battery for highly power-sensitive applications.
The breakthroughs of Epishine and e-peas both can advance energy harvesting solutions in a variety of applications ranging from wireless technology, to Internet of Things (IoT), building automation and even wearable devices. This is due to the fact that the AEM10941 is extremely compact and efficient, requiring only seven external parts, being five capacitors and two inductors according to its product brief, while the Epishine photocells push the capability of organic photovoltaics towards an industry favorite solution of Gallium Arsenide (GaAs), while being a fraction of the cost.
The block diagram for the AEM10941 is shown below, and one can see just how little is needed on the outside in order to effectively use this device.
Figure 1: Functional Block Diagram of the AEM10941. Image Courtesy of e-peas
As we can see from Figure 1, the e-peas PMIC provides Maximum Power Point (MPP) controls to optimize the energy harvesting capability of the system to power a boost/buck-controlled output voltage for charging either a battery, supercapacitor or standard capacitor. Furthermore, two high precision LDOs, one providing a selectable 1.2V or 1.8V DC signal and another providing an adjustable output between 1.8V - 4.1V can provide up to 20mA and 80mA respectively. All resistors and the primary battery shown in Figure 1 are optional, as the primary battery will only be utilized if needed, and the resistors can activate additional functionality settings and feedback loops for the High Voltage (1.8V- 4.1V) LDO and the source input for the cold start control block, along with three configurable pins for additional functionality.
The e-peas, Epishine and CAP-XX based evaluation kit is truly an exceptional solution to a variety of lower power applications, as it is exceptionally efficient at harvesting energy in nonideal conditions while being extremely compact and cost-effective due to the high integration of the AEM10941. These kinds of solutions are needed in order to push to the highly integrated society we are pushing forward to living in, as many independent electronic devices must be powered at all times and have the capability to talk with one another with nonideal power constraints. This collaboration and solution is a great combination of the brain of the AEM10941, the beauty of the organically printed LEH modules from Epishine, and the brawn of the 400mF GA230 supercapacitor from CAP-XX.