PCM-061/phyCORE-i.MX7 System on Module
L-821e_2
© PHYTEC America L.L.C. 2017
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4.3.3
External Battery (VBAT)
The SOM provides a VBAT input for applications requiring an ultra-low power RTC that retains time when VCC_SOM is
removed. Connect a 3.0 V battery or other supply to the VBAT input at pin X1-B57. VBAT voltage should not exceed the
VCC_SOM supply. The RTC will continue to maintain its time down to approximately 1.0V on the VBAT pin.
The VBAT rail also supplies the LICELL pin on the PMIC, allowing for the connection of a coin cell backup battery or super
capacitor. If VCC_SOM goes below the V
IN
threshold of the PMIC or is removed, the VBAT voltage supplied to the LICELL
pin will be switched to maintain power for the internal logic and the VSNVS rail. If VBAT is not present or disconnected,
then the memory will be cleared and VSNVS will be turned off. To prevent this, the VBAT rail should supply the LICELL pin
with a voltage between 1.8V and 3.0V.
For applications that do not require the external RTC backup or PMIC Coin Cell operation, VBAT can be left floating.
