VBAT for STM32F777 / STM32H743 to meet UL certification
Hello,
We are using F777VI and H743VI in our products and we need to meet UL requirement. https://iq.ulprospector.com/en/document?e=206486
Primary cells and batteries are not rechargeable. Secondary cells and batteries are rechargeable. Primary cells and batteries are designated to be either technician replaceable or user replaceable. Secondary lithium ion cells are not intended to be user replaceable. The circuitry containing the primary cells and batteries should include two diodes (or equivalent) to prevent charging current. Alternatively, the circuitry containing primary cells and batteries should include one diode (or equivalent) and a current-limiting device, such as a resistor.
What is the solution you offer, is such capability embedded in ST processors or should be added externally?. It is not very efficient to have diode Drop (0.4V - 0.7V) in a 3V battery coin, or a 2 AA battery (2.4V).
