How to ensure the screen doesn't go black during voltage drops in HMI (Human Machine Delivery) systems?

To ensure the HMI doesn't black out during voltage dips, its core control system must remain operational even with brief drops in input voltage. Voltage dips can cause unstable output voltage or resets in the switching power supply. First, select a switching power supply module with a wide input voltage range and ensure it has sufficient margin. Add a large-capacity energy storage capacitor, such as an electrolytic capacitor, to the input of the switching power supply to provide energy buffering during momentary drops in grid voltage. Sufficient output capacitance is also needed at the output of the switching power supply to maintain voltage stability. For the power rails supplying core chips such as the MCU and SDRAM, in addition to conventional decoupling, consider adding a supercapacitor or a small-capacity backup battery to form a UPS function.

The MCU's reset circuit design must be reasonable; the reset threshold and delay time must be able to withstand brief voltage fluctuations to avoid false resets. The power supply for the display module and backlight should ideally be separate from the core logic power supply and powered by an independent LDO or DC-DC converter. This way, when the logic power supply is disturbed, the display may dim but won't immediately black out. On the software side, upon detecting a voltage dip, critical states can be quickly saved, and a low-power mode can be entered to reduce power consumption. By employing high-performance capacitors and an optimized power architecture design from Eternity, the HMI's resilience to voltage dips can be significantly improved, maintaining the continuity of display and basic functions.