SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
The Power Management Unit in AM263x consists of a Reference system and a Safety system.
The Reference system generates internally used power supply and reference rails. It ensures reliable power on sequencing with the PMU and generates a reset signal based on coarse voltage level checks given to the external power supplies. The Reference system also contains the 1.8V LDO which generates a 1.8V output on the VDDA18_LDO pin. The 1.8V on VDDA18_LDO can be connected to VDDA18 and VDDA18_OSC_PLL on the board to provide the 1.8V supply to the Analog Circuit and PLL. This connection has to be done external to the device as there is no internal connection path for VDDA18_LDO to source either VDDA18 or VDDA_OSC_PLL.
Using the 1.8V LDO as the VDDA18 source allows the 1.8V LDO to source multiple internal blocks. These blocks include the internal ADC voltage reference buffers as well as other analog loads. Because the ADC reference buffers are sourced internally through the VDDA18 input, the VDDA18_LDO output should not be connected as source for the ADC VREFHI inputs.
The Safety System contains the safety comparators and temperature sensor to monitor the system supplies and temperature. The glitch filtered output of the voltage monitors are connected to the Error Signaling Module (ESM) and provide an error signal if the supply is not within the voltage thresholds set for the individual monitored supplies.