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TPS65217CEVM: How to connect unused pin

Part Number: TPS65217CEVM
Other Parts Discussed in Thread: TPS65217, TPS65218D0

I don't want to use charger block on TPS65217C.

How can I connect specific unused pins SYS, BAT, BAT_SENSE, and TS.

I connect VIN_DCDC1,2,3/VINLDO/LDO3,4_IN directly from outside system.

  • Jung,

    You can supply 4-5V DC supply directly to BAT pins. In this case, BAT_SENSE should be shorted to BAT and TS pin should be terminated to GND through a 10kOhm resistor (to mimic a 10kOhm NTC at 25C). When power is only supplied to BAT you will need to press push-button connected to PB_IN to create a wake-up event to the system.

    Alternatively, you can supply 5V DC to AC (or USB) pins. In this case, BAT_SENSE should still be shorted to BAT but this net should be terminated to GND through a 1kOhm resistor. TS can be left floating. When power is supplied to AC (or USB), a push-button press is not required to wake-up the system.

  • Brian, Thank you for your comment.

    I need to explane more.

    I can use another switching charger in my circuit.

    I will supply VINLOD, VIND_DCDC, LDO_IN directily (Not BAT pin). I don't wnat to connect BAT pin.

    Because battery is connected by switching charger.

    In this case. How can I left SYS and BAT Pin?

  • Jung,

    In your case, where you are using separate battery charger, I would consider using the TPS65218D0 instead of TPS65217. This is especially true if you are not using the WLED driver function on the TPS65217 PMIC. TPS65218D0 is still designed for battery-powered systems but it does not integrate battery charger or WLED driver.

    If you must use the TPS65217, you still have 2 options :

    Connect main supply (output from switching battery charger) to AC pin and also to VINLDO & VIN_DCDCx power rail inputs. In this case, BAT_SENSE should still be shorted to BAT but this net should be terminated to GND through a 1kOhm resistor. TS can be left floating. When power is supplied to AC (or USB), a push-button press is not required to wake-up the system. NOTE: SYS pin must also be wired but it can connect to a 4.7uF output capacitor only and not supply power to any of the power rails. The recommended 22uF capacitor can be reduced to 4.7uF because this pin is no longer being used as a current path.

     

    An alternative solution would still be to connect the main supply (output from switching battery charger) to the BAT pins directly and also to VINLDO & VIN_DCDCx power rail inputs. In this case, BAT_SENSE should be shorted to BAT and TS pin should be terminated to GND through a 10kOhm resistor (to mimic a 10kOhm NTC at 25C). NOTE 1: SYS pin must also be wired but it can connect to a 4.7uF output capacitor only and not supply power to any of the power rails. NOTE 2: Because a push-button press is required to wake-up the PMIC when BAT is used as the only supply, a workaround for this would be to short PB_IN to PGOOD. Before power-up sequence, PGOOD is low, which will look like a push-button press. When the systems turns on and the power-up sequence is complete, PGOOD goes high and you will avoid a long-key press (which would happen if PB_IN is low for >8s).

     

    As you can see, it is a little complicated to use TPS65217 when the battery charger is not used. This is why I recommend considering TPS65218D0 instead.