Datasheet

Power Delivery, Signaling, and Reset
August 2016 Intel® Joule™ Datasheet
Document number: 566641 rev. 1.0 Page 12
3 Power Delivery, Signaling, and Reset
3.1 Main power supply (VSYS)
The Intel® Joule™ module requires VSYS source routed through 12 pins, 6 on each board-to-board connector, that must all
be connected in common to balance the current path.
This is the only power input path; voltage detection at +VDC_IN or USB VBUS will trigger module boot.
Caution: It is NOT possible to supply VSYS directly from any USB power supply, as the USB operating
specification of 4.75V to 5.25V may exceed the safe operational range of the module.
3.2 Power on signaling
3.2.1 +VDC_IN power sensing
+VDC_IN is the signal that indicates when the module is being powered from an external power source.
When no RTC battery is present, the system will boot when both +VDC_IN and VSYS are at a valid level.
If an RTC battery is present, the operating system can configure the wake source register of the PMIC to either boot when
+VDC_IN is present, or to wait for a signal on the power button line.
3.2.2 +VBUS power sensing
The +VBUS pin is used by the module to detect if power is present on the USB connector of the attached expansion board. If
the +VBUS pin is within the voltage range specified in Table 5, then the module will initiate a boot.
3.2.3 Power good
The module will assert the PMIC_PWRGOOD signal HIGH after the VDD1 and VDD3 rails are within specification.
3.3 Hard shutdown via power button
The Intel® Joule™ module has a single Power Button pin (PMIC_PWRBTN_N) that will trigger a shutdown of the module when
held LOW for longer than 10 seconds.
Table 5 Boot decision per voltage supply condition
+VDC_IN +VBUS VSYS Action
0 VDC 0 VDC >VSYS (min) No Boot
0 VDC >+VBUS (min) >VSYS (min) Cold Boot
>+VDC_IN (min) 0 VDC >VSYS (min) Cold Boot
>+VDC_IN (min) >+VBUS (min) >VSYS (min) Cold Boot