User Guide

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The DB8 routes the RST_BTN_N (named PM_RESIN_N on DB8 schematic) signal to the RESIN_N pin of the PMI8996 PMIC.
This signal is driven by S4, the on-board reset switch. This signals is a dual purpose, any press lasting less than 10 seconds
serves as Volume Down or Zoom out, a press longer than 10 seconds will reset the board.
6.7 Power Supplies
The 96Boards specification calls for three power rails to be present on the Low Speed Expansion Connector:
●
+1.8V
: Max of 100mA
● +5V: Able to provide a minimum of 5W of power (1A).
● SYS_DCIN : 9-18V input with enough current to support all the board functions or the output DCIN from
on-board DC Connector able to provide a minimum of 7W of power.
The DB8 supports these requirements as follows:
+1.8V
: Driven by PMIC LDO VREG_S4, which can provide 100mA.
+5V : Driven by the 5A 5.0V DC to DC converter (on carrierboard-U37). This buck switcher powers both USB limit current
devices (each at 1.0A max). The remaining capacity provides a max current of 3A to the Low Speed Expansion Connector,
for a total of 8.2W which meets the 96Boards requirements.
SYS_DCIN: Can serves as the board’s main power source or can receive power from the board. It supports a minimum of
7W.