Photon 2 VBAT Pin reverse polarity protection?

Hardware
1

Per the topic question, this appears to have a blocking diode between VBAT and VIN (D7).
What about the implications to the RT9526 Charge Controller?
(schematic snippet below)

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2

I don't entirely understand your question. Diode D7 is to block voltage supplied on VUSB from flowing into the battery, bypassing the charge controller.

Because the Photon 2 uses a charge controller, not a full PMIC, there still needs to be a path to allow the battery to power the device, which is through diode D7 in the forward direction.

This is different on devices with a bq24195 PMIC, where the battery only connects to the PMIC, and the PMIC handles whether the battery is charging or discharging and which power source is used.

1 Like
3

Thanks for clarifying the D7 role @rickkas7
That makes total sense now with your explanation.

To the original question:
Is there ANY protection for the Photon 2 with reverse polarity voltage on the VBAT/LI+?

Thanks in advance.

4

The LiPo battery connector does not have reverse polarity protection. Be careful of this because there is no standard for the polarity of the JST-PH connector and many are reversed. See the battery guide for more information.