Part Number:AM3352
Hi,
We have a design incorporating an AM3352 and TPS65217C (with DDR3L) and would like to support the RTC-Only mode. We are considering the possibility of using either the internal RTC, or a discrete I2C device (as recommended for lowest power consumption).
In the case of the internal RTC, the discussion here suggests the only requirement is to supply an independent 1.8v to VDDS_RTC. However, SPRS717J indicates that RTC_PWRONRSTn should be asserted for at least 1 ms before being released. Is this required, or can it also be provided from 1.8V VDD_ RTC? Also, presumably if RTC alarm or cyclic wakeup is required, then PMIC_POWER_EN should be connected to a circuit that can re-enable 5V supply to the PMIC. Also I believe ENZ_KALDO_1P8V and CAP_VDD_RTC should be grounded and connected via a 1uF decoupling capacitor to ground, respectively. Is this correct?
In the case of a discrete RTC IC, I believe the following is required (according to the data sheet, and errata):
- RTC_PWRONRSTn should be asserted (grounded)
- RTC_KALDO_ENn should be connected to VDDS_RTC (VLDO1)
- CAP_VDD_RTC should be connected to VDD_CORE
- OSC1_IN and OSC_OUT should be disconnected
Is this correct? In addition the discrete RTC presumably needs to separately wake and supply the PMIC when wakeup is required (e.g. RTC alarm). Are there other requirements, e.g. VIO?
Thanks in advance,
Paul
