Figure 7-1 shows the TPS6521902 variant powering the AM62x processor on a system with 3.3 V input supply and LDDR4 memory. Buck1 is the PMIC rail with the highest current rating and it is used to supply VDD_CORE. LDO2 supplies VDDR_CORE. Buck2 and Buck3 supply the 1.8V IO domain and the 1.1V LPDDR respectively. LDO1, configured as bypass, allows dynamic SD card voltage changes between 3.3 V and 1.8 V. This voltage change on LDO1 can be triggered by I2C or by setting the VSEL_SD pin high (LDO1=3.3 V) or low (LDO1=1.8 V). LDO3 supplies the 1.8V analog domain. LDO4 are 2.5V free power resource that can be used to supply external peripherals like the Ethernet PHY. This NVM variant also has GPO2 pre-programmed to enable an external discrete IC. When using a 3.3V input supply, GPO2 can be used to enable an external power-switch that supplies the system 3.3V IO. This power switch must be selected with the right electrical spec to ramp and provide a stable output voltage within the 10 ms duration (before the PMIC start the next slot in the power-up sequence). GPIO and GPO1 are free digital resources that are disable by default but could be enabled through I2C if needed.

The TPS6521902 also supports 5V input supply. When using VSYS = 5 V, replace the external power-switch with a 3.3 V Buck converter. This external buck converter is enabled by the same PMIC GPO2.

Figure 7-1 TPS6521908 Powering AM625SIP