Hi to everybody,
I'm designing a board based on DM3730. I'm using TPS65023 as the power supply regulator.
My configuration is:
DCDC3=1.8V (IO,MEM,DRAM...); DCDC2=1.15V (CORE); DCDC1=1.2V (MPU_IVA); LDO1=1.8V (DPLL); LDO2=3.3V (MMC)
I am going to follow "OMAP35x-AM37x-DM37x with TPS65023: Design In Guide" schematic to create the power up sequence:
DCDC3 will be enabled first using Vin. Its output is reduced to 1.15V by a resistor divider and connected to POWERFAIL_SNS. This signal will be internally compared to 1V and then it will generate a signal through #POWERFAIL pin that is connected to DCDC2_EN and LDO_EN.
DCDC2 output (1.15V) will be connected to LOWBAT_SNS and #LOWBAT output to DCDC1_EN.
#RESPWRON will be released at this time.
I have several questions regarding this power up sequence of the DM3730:
- Is it a problem that LDO2 (3.3V) turns on at the same time as DCDC2 and LDO1 and before the mpu_iva? I am doing this since I might want to boot from a SD card.
-Is the input voltage at pin POWERFAIL and LOWBAT (1.15V) correct in order to achieve the power up requirements?
Thanks a lot in advance,
Nubba.
