Problem connection with ethernet port use 3.3V external power supply

[juanolivero]

Hi.
I need help with the following problem.
I am using an FRDM-K64F powered with an external 3.3V source.
When connecting ethernet port to pc, sometimes does not connect pc with K64F. After restarting the external source several times connect.
I can not find the reason. Can it be bad configuration of the ethernet port of the K64F? Problem in the transient current of the external source?
Thank you. Greetings.
Juan.

[Hui_Ma]

Hi

If customer using J24 provided power to FRDM-K64F board? Please check the power source driver capability.

Thank you for the attention.

Have a great day,
Ma Hui
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[juanolivero]

Hola Hui_Ma

I designed the hardware around the FRDM-K64F. But this is simple, it consists of a power source of 3.3v @ 100mA. In addition to analog / digital inputs / outputs.  I energized the K64F through the pins 4 and 6 of the J3 (P3V3). Is this advisable? Or it is best to do it through the pin 16 (J3) 5_9V or J24 connector?

The problem is after the K64 is running in continuous mode. If there is a power outage when resetting in the short time (10 sec), it does not connect the K64's ethernet port to the network.

[Hui_Ma]

Hi

We prefer to add the voltage at J24 or pin 16 (J3) 5_9V with FRDM-K64F U17 NCP1117ST33T3G regulator, which provides the K64 3.3V voltage.

While, from the NCP1117ST33T3G regulator datasheet, the VIN voltage should be in range of [4.75V to 10V].

Wish it helps.

Have a great day,
Ma Hui
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