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Power & Boot

Power Supply Specifications

The Rhino Core Q85 intelligent module uses the Qualcomm PMIC power solution and receives power through the board-to-board connector.

SignalTypeVoltage RangeDescription
VBATTMain power input3.5V ~ 4.2VMain power supply for the core board, typical value 3.8V
USB_VBUSUSB charging input3.7V ~ 21.5VSupports QC5.0 fast charging

Power Outputs

The core board provides multiple regulated outputs through the PMIC for carrier board peripherals:

Output SignalVoltageDescription
VREG_BOB1Adjustable Buck/BoostPowers the CODEC IC
VREG_S6G_1P861.8VGeneral-purpose 1.8V output
VREG_L8B_1P81.8VPowers the SD card signal level shifter
VREG_L6B_1P81.8VGeneral-purpose 1.8V output
VREG_1P2_SYS1.2VPowers the SD card signal level shifter
VREG_L13B_3P03.0VGeneral-purpose 3V output
VREG_L14B_3P23.2VGeneral-purpose 3.2V output
VREG_L15B_1P81.8VGeneral-purpose 1.8V output
VREG_L16B_2P82.8VGeneral-purpose 2.8V output
VREG_L9B_2P91.8V / 2.95VTF card power supply

Power Sequencing

The core board integrates the Qualcomm PMIC power management chip. The power-up sequencing is automatically managed by the PMIC, so the carrier board design does not need to handle the core board power sequencing separately. The carrier board only needs to provide a stable VBATT supply.

Reset Signals

SignalTypeActive LevelDescription
PM_RESIN_NInputActive lowReset signal; pulling low triggers a core board reset
PM_CBL_PWR_NInput/OutputActive lowPower-on configuration signal; pulling low enables power-on auto-start

Power On/Off Control

SignalTypeActive LevelDescription
KPD_PWR_NInputActive lowPower key signal

For the carrier board design, it is recommended to connect KPD_PWR_N to ground through a key: short press to power on, long press to force power off. Grounding PM_CBL_PWR_N enables automatic power-on on boot.

Boot Media

The core board boots from UFS by default. The system firmware is flashed to the on-board UFS storage, and the bootloader is loaded from UFS after power-on.

Flashing Mode

SignalDescription
FORCE_USB_BOOTFlashing mode enable signal; when enabled, the module enters download mode via USB

Steps to enter flashing mode:

  1. Ground the FORCE_USB_BOOT signal
  2. Power on the core board
  3. Connect the host via USB and use the Qualcomm flashing tool to flash the firmware

RTC Backup Power

SignalTypeDescription
VCOINInput/OutputRTC backup power input

When VBATT is disconnected, VCOIN can supply backup power to the RTC. It is recommended to connect an external large capacitor or coin cell battery. Power consumption is about 10μA after VBATT is disconnected; choose the appropriate capacitor or battery as needed.