Hello,
Please help to check the below connection is worked strap mode 1 for LED_0? Because 1.8-V supply results in dim LED lighting, so the customer referred to Figure 27 for a possible implementation of this functionality.
Best regards
Kailyn
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Hello,
Please help to check the below connection is worked strap mode 1 for LED_0? Because 1.8-V supply results in dim LED lighting, so the customer referred to Figure 27 for a possible implementation of this functionality.
Best regards
Kailyn
Hi Kailyn,
You mention this is a screenshot from Figure 27, which document is this captured from?
Strap modes are determined by the voltage sensed on the strap pin. If the PHY is using a 1.8V supply for VDDIO, the strap pins, including LEDs should be pulled up to 1.8V. Pulling the LED pin up to 3.3V while a 1.8V supply is used for VDDIO will result in an incorrect strap mode.
Thank you,
Nikhil
Hi Kailyn,
Yes this configuration you have shown should be ok.
Thank you,
Nikhil
Hi Kailyn,
To clarify, DP8386IR/CR datasheet defines the strap modes as mode 1-4. The strap settings can be found in section 8.5 of the datasheet. The image you have shown above would be consistent with a mode 1 setting. Figure 27 shows a mode 2 setting. To convert Figure 27 to mode 3, the 10k resistor should be replaced by a 5.76k resistor.
Figure 26 in the datasheet, showing the direct pull-down to GND, is the mode 1 configuration used for a higher VDDIO level. As you mentioned the desired VDDIO level is 1.8V, the recommended mode 1 configuration would be as you have shown above, to ensure the LED will illuminate as expected.
Please let me know if you have any further questions.
Thank you,
Nikhil