The external power supply input
monitors supported by the processor can be used for early detection of power supply
failure or power supply diagnostics.
The processor families support below
voltage monitors:
- 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 device-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 a 1.8V supply to be monitored directly to the VMON_1P8_SOC and
VMON_1P8_MCU (without any filter capacitor) pins. For the allowed supply
voltage range, see the Recommended Operating Conditions section of
the device-specific data sheet. When the voltage monitor is not used, follow
the Pin Connectivity Requirements to connect the VMON_1P8_SOC and
VMON_1P8_MCU inputs.
- The recommendation is to
connect a 3.3V supply to be monitored directly to the VMON_3P3_SOC and
VMON_3P3_MCU (without any filter capacitor) pins. For the allowed supply
voltage range, see the Recommended Operating Conditions section of
the device-specific data sheet. When the voltage monitor is not used or 3.3V
IO supply is not available, follow the Pin Connectivity Requirements
to connect the VMON_3P3_SOC and VMON_3P3_MCU inputs.
Note: AM243x ALX package does not support VMON_3P3_MCU and
VMON_1P8_MCU voltage monitor inputs.
For more information, see the
following FAQs:
[FAQ] AM625 / AM623 / AM620-Q1 / AM62Ax /
AM62D-Q1 / AM62Px / AM64x / AM243x (ALV) Design Recommendations / Custom board
hardware design – POK VMON Voltage Monitor
[FAQ] AM625 / AM623 / AM620-Q1 / AM62Ax /
AM62D-Q1 / AM62Px / AM64x / AM243x (ALV, ALX) Design Recommendations / Custom
board hardware design – Power OK (POK) Module Voltages Monitored and Connection
recommendations