User's Manual l TQMa8XxS UM 0101 l © 2022, TQ-Systems GmbH
Page 33
The following figure shows the switch-on sequence of the controllers, as well as the enable signal:
Figure 31:
Power-up sequenz PMIC
Attention: Power-Up sequence
To avoid cross-supply and errors in the power-up sequence, no I/O pins may be driven by external
components until the power-up sequence has been completed.
The end of the power-up sequence is indicated by a high level of signal V_1V8.
To ensure a correct power-up, the following sequence must be met on the carrier board:
The supply voltage of 3.3 V for the TQMa8XxS is present and the carrier board supply of 3.3 V
is activated with TQMa8XxS voltage V_1V8.
3.8.4
PMIC
The PF8100 with TQ-specific OTP programming is used on the TQMa8XxS as standard. The PMIC is connected to a dedicated I2C
bus of the processor for power management (PMIC_I2C).
i.MX 8X
PF8100
SMARC-Pins
PMIC_STBY_REQ
PMIC_ON_REQ
VIN_PWR_BAD#
CARRIER_PWR_ON
PGOOD
POR_B
RESETBMCU
IMX_POR#
RESET_IN#
RESET_OUT#
RESET_IN#
I2C
I2C_PM_xx
PMIC_I2C
PWRON
STANDBY
SCU_PMIC_STANDBY
PMIC_ON_REQ
VIN_PWR_BAD#
PMIC_INT#
INTB
PMIC_INT_B
RESET_OUT#
Figure 32:
Block diagram PMIC signals
