About ADP5080 Pin  Impedance

Hi, 

My customers are evaluating using ADP 5080, but it does not start up even when EN is set to the high level. When VIN 5 is opened and EN is set to High, it is in a state to rise.
Also, when VIN5 was open, the boosted voltage was seen as same as CP.

From the above, I have a question.

① Is there a specification of impedance value between input pin and GND, BSTCP pin and input pin (VIN5 etc.)? I am

  also considering the possibility of a short circuit.

② If the impedance value of ① is not specified, what impedance can be confirmed, is there any indicator such as "abnormality"?

Best Regards

Yuya

  • 0
    •  Analog Employees 
    on Nov 9, 2017 12:24 PM over 3 years ago

    Hi,

     

    PVIN5 is for power of high-side driver. So normally PVIN impedance is very high at OFF condition.

    In addition, I assume this phenomenon that ADP5080 can operate at opening theVIN5 has been caused by the damage on the PVIN5 pin or BST5 or VDR5.

    On the other hand, ADP5080 has mode selection at register settings. as a default, channel 5 is I2C mode so it doesnt affect to the other channels and EN pin. However if it affects to the other channels w/ I2C mode, VDR5 would have some damage.

     

    Please check your customer the following things.

    -Have you changed the SEQ_MODE register for channel 5 from I2C mode to Sequence mode?

    -If so, please check BST voltage, VDR  or VREG1 and Vout5 to see what happens on.

    ADP5080 has under voltage delay protection. (UVP_delay =21ms after detecting the low output voltage)

  • Hi, takahiro.kadokawa

    I'm sorry that the reply was delayed.
    Thank you for your advice.
    We will check the contents you gave us advice.

    Best Regards

    Yuya