SPRADO3B December 2024 – September 2025 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
For the voltage monitor pin VMON_VSYS the recommendation is to always provision for external resistors (voltage divider) for early detection (indication) of supply failure irrespective of the software implementation. The recommendation is to connect 5V or above for the detection to be effective. For connecting the on-board voltage (main supply voltage such as 5V or 12V or 24V) through an external resistor voltage divider, see the System Power Supply Monitor Design Guidelines section of the processor-specific data sheet. The recommendation is to implement a noise filter (capacitor) at (across) the resistor output connected to the VMON_VSYS input since VMON_VSYS has minimum hysteresis and a high-bandwidth response to transients.
The recommendation is to connect VMON_1P8_SOC and VMON_3P3_SOC pins directly to the respective supplies (without any external filter capacitor added). See the Recommended Operating Conditions section of the processor-specific data sheet for the allowed supply voltage range.
For VMON_VSYS, fail-safe condition is valid when the recommendations in section System Power Supply Monitor Design Guidelines of processor-specific data sheet are followed.
For VMON_1P8_SOC and VMON_3P3_SOC pins, fail-safe condition is valid when the supply voltage connected is within the Recommended Operating Conditions section of processor-specific data sheet.
For more information, see the following FAQs: