AM437x low power suspend mode using LPDDR2

This low-power mode scheme achieves processor power consumption of less than 0.1 mW while maintaining LPDDR2 memory power consumption in the self-refresh state at approximately 1.6 mW. The system solution consists of AM437x Sitara processor, LPDDR2 memory and TPS65218 power management IC, and has been optimized for new low-power modes while supporting traditional low-power modes. Minimize processor power by turning off all processor power except the RTC power. System power state transitions, including power control, can be performed by a single interface signal (PMIC_PWR_EN signal) using PMIC register programming.

characteristic

• ● Suspend to RAM in lowest system power mode
  • ● AM437x in RTC-only mode
  • ● TPS65218 is in pending state
  • ● LPDDR2 is in self-refresh state
• ● The system can be restored to the state it was in before suspending
• ● Only RTC suspend power consumption
  • ● AM43x + TPS65218: < 0.1 mW
  • ● Typical 2Gb LPDDR2: 1.6 mW
• ● How to suspend events:
  • ● Programming through RTC register
  • ● By setting RTC alarm
• ● Recovery events:
  • ● RTC alarm sounds
  • ● PMIC button or AC power detection
• ● Recovery time
  • ● Hardware latency less than 300 milliseconds
  • ● Software recovery to previous state takes less than 1 second (depends on application usage)
• ● This design has been tested and includes schematics, BOM, and design guidelines.