Apalis iMX6 Issue Tracker

The following table contains known issues, scheduled bug fixes, and feature improvements for the Apalis iMX6.

For other information, click on the below links:

Issue #	Status	Subject	Affected Versions	Implemented In
HAR-8210	Known Issue	POWER_ENABLE_MOCI indeterminate due to backfeeding on Apalis iMX6	Apalis iMX6 1.1A
Customer Impact: Depending on the carrier board and backfeeding, the POWER_ENABLE_MOCI might not go low enough to turn off the peripheral voltage rails in the shutdown state. Description: The POWER_ENABLE_MOCI signal is intended to be used for switching the peripheral voltage rails on the carrier board, like the 5V_SW and 3.3V_SW on the Ixora. Depending on the mount of backfeeding over the interface signals from the carrier board to the Apalis iMX6 module, the POWER_ENABLE_MOCI signal can remain between 1.0V and 1.4V in module shutdown. Depending on the carrier board circuit, this can be too high for turning off the peripheral voltage rails. For example, on the Ixora V1.2, a different buck converter for the 5V_SW is used than on the previous versions. The threshold voltage for the enable signal is lower on the new buck converter. Depending on the backfeeding level, the 5V_SW buck converter does not get disabled in the shutdown state. The Ixora V1.0 and V1.1 are not affected by this issue since they used a different buck converter with a higher threshold. Workaround: Add a circuit for increasing the POWER_ENABLE_MOCI threshold voltage between 2.0V and 2.5V This could be achieved by adding a comparator or similar circuit. Such a solution is implemented in the V1.3 revision of Ixora. A simple voltage divider at the POWER_ENABLE_MOCI signal can shift the voltage levels. Important: make sure the minimum input voltage for enabling the buck converter is still guaranteed. With the AOZ2260 buck converter that is used on Ixora V1.2, a 10k/10k voltage divider can be a suitable option. For patching such a divider, replace R15 with 10k 0603 resistor and add another 10k resistor from the PMIC_EN_5V signal to the ground.

Issue #

Status

Subject

Affected Versions

Implemented In

HAR-8210

Known Issue

POWER_ENABLE_MOCI indeterminate due to backfeeding on Apalis iMX6

Apalis iMX6 1.1A

Customer Impact: Depending on the carrier board and backfeeding, the POWER_ENABLE_MOCI might not go low enough to turn off the peripheral voltage rails in the shutdown state.

Description: The POWER_ENABLE_MOCI signal is intended to be used for switching the peripheral voltage rails on the carrier board, like the 5V_SW and 3.3V_SW on the Ixora. Depending on the mount of backfeeding over the interface signals from the carrier board to the Apalis iMX6 module, the POWER_ENABLE_MOCI signal can remain between 1.0V and 1.4V in module shutdown. Depending on the carrier board circuit, this can be too high for turning off the peripheral voltage rails. For example, on the Ixora V1.2, a different buck converter for the 5V_SW is used than on the previous versions. The threshold voltage for the enable signal is lower on the new buck converter. Depending on the backfeeding level, the 5V_SW buck converter does not get disabled in the shutdown state. The Ixora V1.0 and V1.1 are not affected by this issue since they used a different buck converter with a higher threshold.

Workaround: Add a circuit for increasing the POWER_ENABLE_MOCI threshold voltage between 2.0V and 2.5V This could be achieved by adding a comparator or similar circuit. Such a solution is implemented in the V1.3 revision of Ixora. A simple voltage divider at the POWER_ENABLE_MOCI signal can shift the voltage levels. Important: make sure the minimum input voltage for enabling the buck converter is still guaranteed. With the AOZ2260 buck converter that is used on Ixora V1.2, a 10k/10k voltage divider can be a suitable option. For patching such a divider, replace R15 with 10k 0603 resistor and add another 10k resistor from the PMIC_EN_5V signal to the ground.