Energy storage device mcu application

What is MCU for EIoT?

Firstly, the MCU for the eIoT usually has multiple supply domains. For example, apart from the normal supply source, MCUs for smart meters also have a battery supply. Furthermore, the real-time clock (RTC) block is required in the MCU for energy metering. It needs to be working uninterrupted when the meter is in storage or under the power outage.

How much power does an MCU use?

In terms of current consumption, the back end consumes 42.6 mA average current consumption during transmission, and 8.6 mA during reception. During idle, when the MCU is in ultra-low-power operation mode (LPM), the average current consumption is 3.7 μA.

How does a PMU work?

To address this, an energy storage module is included with the PMU. The system harvests energy through the TEG and stores it in the energy storage module. Once enough energy is stored, the PMU rises the signal \ (V_ {PGOOD}\) indicating to the back-end module that the wireless transmission is energetically feasible and can be done.

Are ultra-low-power MCUs a good choice for EIoT applications?

State-of-the-art ultra-low-power MCUs on the market can achieve submicrowatt power consumption in low-power mode; however, they can only supply a single standard 3.3-V supply voltage , which requires additional power switching circuit on-board, increasing the design cost for eIoT applications.

What is the output voltage of a MCU if VDD is small?

When VDD is small (less than VI3 + VGS,NM0), the transistor NM4 enters the linear region, and the output voltage is about VDD − VGS,NM1. Since the battery voltage changes in its lifetime, the MCU is usually required to have a wide operating voltage range, such as 2.2 V~5.5 V.

Do energy IoT devices work under the main power supply?

Furthermore, devices in energy IoT (eIoT) do not always work under the main power supply. When the main power supply is unavailable, the standby power supply (usually the battery) needs to maintain the operation and save the data.