• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 62 subscribers
  • Views 751 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS2115A: Output Voltage is not 0V if only one power supply is connected

Patrick Morger53
Prodigy 40 points
Part Number: TPS2115A

We use the TPS2115A in autoswitch mode and have connected two 5V0 power supplies to the device.

for VIN1 = 5.0V and VIN2 = 0.0V the output voltage is ~100mV 

and 

for VIN1 = 0.0V and VIN2 = 5.0V the output voltage is ~1000mV

My question is why is there an output voltage of 100mV or. 1000mV? I did expect that the output voltage is 0V

Best Regards

Patrick

  • 0
    TI__Genius 15710 points

    Hi Patrick,

    In your setup, is there a load connected to the output? There is no output pulldown circuitry in this device, so the output is essentially floating and may not show 0V without a load connected.

    Thanks,

    Alek Kaknevicius

  • 0 in reply to Aleksandras_Kaknevicius
    Prodigy 40 points
    Hi Alek,

    Thank you for your reply.

    I did measure my circuit again and it was not the output voltage not equal 0V. It was the other Input voltage without connecting any voltage:

    for VIN1 = 5.0V and VIN2 not connected the output voltage is 5.0V but VIN2 is ~100mV

    and

    for VIN1 not connected and VIN2 = 5.0V the output voltage is 5.0V but VIN1 is ~1000mV

    My question is why is there an input voltage of 100mV or. 1000mV on the not used channel? I did expect that the input voltage is 0V
  • 0 in reply to Patrick Morger53
    TI__Genius 15710 points

    Hi Patrick,

    If the input is left floating (not connected to any power supply or pull down circuitry) then it may float at a nonzero voltage. When the inactive channel is blocking reverse current, there is a leakage current from OUT to IN of 0.3uA (typ.). This current can cause the voltage to float higher than 0V.

    Thanks,

    Alek Kaknevicius