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Power Supply Implementation Guidelines
5 volt input power is the sole operational power source for the conga-QA6. The remaining necessary voltages are internally generated on the
module using onboard voltage regulators. A carrier board designer should be aware of the following important information when designing a
power supply for a conga-QA6 application:
• It has also been noticed that on some occasions problems occur when using a 5V power supply that produces non monotonic voltage when
powered up. The problem is that some internal circuits on the module (e.g. clock-generator chips) will generate their own reset signals
when the supply voltage exceeds a certain voltage threshold. A voltage dip after passing this threshold may lead to these circuits becoming
confused resulting in a malfunction. It must be mentioned that this problem is quite rare but has been observed in some mobile power
supply applications. The best way to ensure that this problem is not encountered is to observe the power supply rise waveform through
the use of an oscilloscope to determine if the rise is indeed monotonic and does not have any dips. This should be done during the power
supply qualification phase therefore ensuring that the above mentioned problem doesn’t arise in the application. For more information
about this issue visit www.formfactors.org and view page 25 figure 7 of the document “ATX12V Power Supply Design Guide V2.2”.
Inrush and Maximum Current Peaks on VCC_5V_SB and VCC
The inrush-current on the conga-QA6 VCC_5V_SB power rail can go up as high as 2.3A for a maximum of 100µS. Sufficient decoupling
capacitance must be implemented to ensure proper power-up sequencing.
The maximum peak-current on the conga-QA6 VCC (5V) power rail can be as high as 3.0A. This requires that the power supply be properly
dimensioned.
Note
For more information about power control event signals refer to the Qseven
®
specification.
5.16
Power Management
ACPI 3.0 compliant with battery support. Also supports Suspend to RAM (S3). No support for legacy APM.
5.17
I²C Bus
The I²C bus is implemented through the use of STMicroelectronics STM32F100R8 microcontroller. It provides a multi-master I²C Bus that has
maximum I²C bandwidth.
