Kontron nanoETXexpress-SP, User Manual

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nanoETXexpress-SP/Specification
3.11.9 Power Control
Power Supply
The nanoETXexpress-SP has a wide range power input from 4.75 - 14V. The supply voltage is applied through the VCC
pins (VCC) of the module connector.
Power Button (PWRBTN#)
The power button (Pin B12) is available through the module connector described in the pinout list. To start the
module via Power Button the PWRBTN# signal must be at least 50ms (50ms ≤ t < 4s) at low level (Power Button Event).
Pressing the power button for at least 4seconds will turn off power to the module (Power Button Override).
Power Good (PWR_OK)
The nanoETXexpress-SP provides an external input for a power-good signal (Pin B24). The implementation of this
subsystem complies with the COM Express™ Specification. PWR_OK is internally pulled up to 3.3V and must be high
level to power on the module.
Reset Button (SYS_RESET#)
The reset button (Pin B49) is available through the module connector described in the pinout list. The module will
stay in reset as long as SYS_RESET# is grounded.
ATX Mode / Single Supply Mode
ATX Mode:
By connecting an ATX power supply PWR_OK is set to low level and VCC is off. Press the Power Button to
enable the ATX PSU setting PWR_OK to high level and powering on VCC. The ATX PSU is controlled by the PS_ON#
signal which is generated by SUS_S3# via inversion.
State PWRBTN# PWR_OK V5_StdBy PS_ON# VCC
G3 x x 0V x 0V
S5 high low 5V high 0V
S5 S0
→
PWRBTN Event low high
→
5V high low
→
0 V VCC
→
S0 high high 5V low VCC
Single Supply Mode or automatic power on after power loss:
In single supply mode the module will start
automatically when VCC power is connected and Power Good input is open or at high level (internal PU to 3.3V).
PS_ON# is not used and 5V_StdBy is not important (no difference if connected or not) in this mode.
To power on the module from S5 state press the power button or reconnect VCC
State PWRBTN# PWR_OK V5_StdBy VCC
G3 x x x 0
G3 S0
→
high open / high x connecting VCC
S5 high open / high x VCC
S5 S0
→
PWRBTN Event open / high x reconnecting VCC
All columns marked with an “x” are not important for the specific power state.
All ground pins have to be tied to the ground plane of the carrier board.
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