3.3. RTC & Power-Button¶
Pin |
Signal |
Description |
type |
I/O |
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|---|---|---|---|---|---|---|---|---|---|
13 |
VBACKUP |
DS1339 RTC backup power supply. Supply voltage must be held between 1.3V and 3.7V for proper RTC operation. This pin can be connected to a primary cell such as a lithium button cell. Additionally, this pin can be connected to a rechargeable cell or a super cap when used with the trickle charge feature. Refer to DS1339 datasheet for details. |
power |
I |
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Module |
Remark |
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TX25 |
Connected to BAT_VDD DRYICE backup power supply input, max. 1.55V The i.MX25 internal RTC is not supported |
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TX6 without DS1339 |
i.MX6 RTC backup power supply. Supply voltage must be held between 2.9V and 3.3V for proper RTC operation. |
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14 |
PMIC_PWR_ON |
PMIC dependent Function. Leave unconnected if not used. |
I |
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Module |
Remark |
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TX25 |
No PMIC onboard - Not connected |
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TX28 |
PSWITCH - Used for chip power on or recovery. PSWITCH is at MID level by default. Refer to i.MX28 reference manual for details. |
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TX27, TX51 |
This is an active high push button input which can be used to signal PWR_ON and PWR_OFF events to the CPU by controlling the PMIC EXT_WAKEUP. Refer to LP3972 datasheet, page 49 for details. |
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TX48, TX53 |
Connected to LTC3589 WAKE. To power down, drive this pin LOW. Refer to LTC3589 datasheet, page 29 for details. |
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TX6 |
Connected to PMIC ON. Refer to PMIC datasheet for details. |
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