Power Delivery, Signaling, and Reset

The power specifications stated herein apply to the capabilities of the Intel® Joule™ module itself. The power specifications will vary for the reference expansion board designed by Intel or for a carrier board that you design yourself. See the Power Subsystem and Accessory Signaling topic in the Expansion Board Design Guide and Powering the Expansion Board in the Expansion Board Hardware Datasheet for more details.

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_SENSE or +VBUS_SENSE 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.

 

+VDC_IN_SENSE +VBUS_SENSE VSYS Action
0 VDC 0 VDC > +VSYS (min) No Boot
0 VDC > VBUS_SENSE (min) > +VSYS (min) Cold Boot
> VDC_IN_SENSE (min) 0 VDC > +VSYS (min) Cold Boot
> VDC_IN_SENSE (min) > VBUS_SENSE (min) > +VSYS (min) Cold Boot

Power on Signaling

VDC_IN_SENSE power sensing

VDC_IN_SENSE 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_SENSE and VSYS are at a valid level.

VBUS_SENSE power sensing

The VBUS_SENSE pin is used by the module to detect if power is present on the USB connector of the attached expansion board. If the +VBUS_SENSE pin is within the voltage range specified in the table below, then the module will initiate a boot.

Power good

The module will assert the PMIC_PWRGOOD signal HIGH after the VDD1 and VDD3 rails are within specification. Expansion board and mezzanine board designs must ensure that circuitry does not interfere with the state of the compute module boot strap pins. See the Boot Strap Signal Isolation in the Expansion Board Design Guide for details.

Power button behavior

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.
  • trigger standby mode on the module when held LOW for more than 2 seconds but less than 10 seconds.

System voltage rail specifications

Rail Name

Voltage

Current

Direction Usage
Min Typ Max Units Min Max Units
+VSYS 3.6 4 5.25 Volts   4 Amps Input Powers the core logic and radios. Recommend using 5V if using the CSI cameras
+VDD3 3.1 3.3 3.45 Volts   300 mA Output General use. Powers on prior to VDD1
+5P0V_VCONN 4.75 5 5.25 Volts   300 mA Input Voltage for USB-C VCONN to CC1 or CC2
+VDD1 1.71 1.8 1.89 Volts   300 mA Output General use. Power on after +VDD3
+VRTC 2.05   3.3 Volts 20 500 uA Input RTC backup voltage - supplies voltage to RTC logic when the system is not-powered.

Power sense signals

Name

Voltage

Current

Direction Usage
Min Typ Max Units Min Max Units
VBUS_SENSE 4 5 20 Volts   20 uA Input Voltage sense for +VBUS power
VDCIN_SENSE 4 12 20 Volts 20 20 uA Input Voltage sense for +VDC_IN power
VBATT_SENSE 0 3.8 5 Volts <20   uA Input Voltage detection for battery. May be used to configure battery voltage as a gate to boot.

 

For more complete information about compiler optimizations, see our Optimization Notice.