SLUAAK2 November   2022 AM625

 

  1.   Abstract
  2.   Trademarks
  3. 1Power Requirements
    1. 1.1 Power on Sequence
    2. 1.2 Power-Off Sequence
  4. 2Schematic
  5. 3Bill of Materials
  6. 4Waveforms
  7. 5Sequencing VDD_CORE and VDDR_CORE Rails
  8. 6Summary
  9. 7References

1 Power Requirements

AM62x requires four to eight power supply groups, depending on the system requirements. The power supply groups include the core supply (VDD_CORE), RAM supply (VDDR_CORE), DDR PHY IO supply (VDDS_DDR), 3.3 V digital supply (VDDSHVx), SD Card interface supply (VDDSHV5), 1.8 V digital supply (VDDSHVy), 1.8 V analog supply (VDDA_1P8) and a 1.8 V eFuse programming supply (VPP).

Figure 1-1 shows a block diagram of the power tree of the AM62x with DDR4. The different voltage regulators for these rails were chosen based on cost, good efficiency, load transient performance, and power up/down sequencing requirements.

The LM61460-Q1, buck converter is used to supply the 3.3V, VDDSHVx rail as well as act as the input supply for the rest of the voltage regulators, except the TLV7103318 in the power tree. VDDSHVy, VDDS_DDR, VDD_CORE and VDDR_CORE are supplied by the TPS6282x family of buck converters. These are high efficiency small solution size buck converters having controlled turn on and turn off times. The VDDA_1P8 and VPP are supplied by 2 LDOs - TPS74518 and TLV75518 respectively. The VDDSHV5 (SD Card IO power supply) rail can be configured to run either at 3.3 V or 1.8 V and is powered using a TLV7103318 LDO. A couple of logic gates along with an RC delay is also required for proper sequencing of the VDD_CORE and VDDR_CORE rails. A detailed circuit schematic detailing the power solution and sequencing is shown in Figure 1-1.

Figure 1-1 Functional Block Diagram of AM62x Power Tree with DDR4 (1.2 V)

The AM62x power requirements are listed in Table 1-1.

Table 1-1 AM62x Power Requirements
Power Supply VOUT (V) IOUT (mA) Output Voltage (V) Power Supply Nominal Rating Grouping
LM61460-Q1 Adjustable 6000 3.3 VDDSHV_MCU, VDDSHV0, VDDSHV2, VDDSHV3, VDDSHV_CANUART, VDDA_3P3_USB, VMON_3P3_SOC 3.3 V ±5% VDDSHVx
TLV7103318 3.3, 1.8 200 3.3 / 1.8 VDDSHV5 3.3 V ±5%
1.8 V ±5%		 VDDSHV5
TPS74518 1.8 500 1.8 VDDA_MCU, VDDA_PLL0, VDDA_PLL1, VDDA_PLL2, VDDA_1P8_CSIRX0, VDDA_1P8_OLDI0, VDDA_1P8_USB, VMON_1P8_SOC, VDDA_TEMP0, VDDA_TEMP1 1.8 V ±5% VDDA_1P8
TPS6282518 1.8 2000 1.8 VDDSHV1, VDDSHV4, VDDSHV6, VMON_1P8_SOC, 1.8 V ±5% VDDSHVy
TPS62824 Adjustable 2000 1.2 VDDS_DDR, VDDS_DDR_C 1.2 V ±5% VDDS_DDR
TPS62826 Adjustable 3000 0.75 VDD_CORE, VDD_CANUART, VDDA_CORE_CSIRX0, VDDA_CORE_USB, VDDA_DDR_PLL0 0.75 V ±5% VDD_CORE
TPS62824 Adjustable 2000 0.85 VDDR_CORE 0.85 V ±5% VDDR_CORE
TLV75518 1.8 500 1.8 VPP 1.8 V ±5% VPP