43
OSD3358-SM-RED
– User Guide
Rev. 1.0 9/19/2017
Octavo Systems LLC
Copyright 2017
4.4
PMIC-AM3358 interface
As discussed in sections 4.1 and 4.2, functions of the PMIC include: proper power up of the
processor, monitoring of the AM3358 power rails, interrupt generation and reset management of
the processor. To perform these functions, the PMIC and AM335x must be connected. These
connections can be found in the datasheet (
https://octavosystems.com/docs/osd335x-sm-
). Figure 41 shows some of these connections in OSD335x-SM-RED schematics.
Figure 41: OSD3358-SM-RED PMIC - AM3358 interface
NOTE:
Due to the input voltage requirements of the TL5209 LDO that supplies
SYS_VDD1_3P3V of the OSD335x-SM, the voltage of the battery that will power the board
needs to be greater than 3.7 V. If the voltage of the battery falls below this threshold,
SYS_VDD1_3P3V begins to go out of regulation resulting in some of the on board
components powered by this voltage rail not working in spec. This includes the SD card
slot and the eMMC, which are the main boot sources for the board.
NOTE:
I2C0 lines are internally pulled up to 3.3 V using 4.7K resistors. In addition, 1.5K
resistors were used to pull up the I2C lines in the RED board. Please see:
(
http://www.ti.com/lit/an/slva689/slva689.pdf
) for more information on how to calculate I2C
pull ups.
NOTE:
Test points TP21, TP22, TP23 and TP24 are provided to monitor these signals for
debug purposes.
