How to solve LTC4446 problems?

LTC4446 is used as a driver for high-side and low-side outputs. Load is inductive (200uH), Vin=60V, Vcc=12V.

LTC4446 fails to operate after several hours. The symptoms are, in a case, excessive current through Vcc (12V), and in other case excessive current through the Tinp and/or Binp digital inputs.

  • Hello Ungan,

    With an inductive load a diode (from ground to top source) and good layout is required to keep the top source from going too far below ground and violating the ICs abs max ratings (BST-TS and/or TS). This could be the problem or Vcc voltage could be too high (abs max is only 14V). I would suggest verifying pin voltage and temperature.

  • Hello Kurk,

    Thank you for the response. I've already used 12V TVS between BST and TS, and a 60V TVS between TS and GND (inductive load side) and a 12V TVS between Vcc and GND. Anyway I will recheck the voltage transients. Or may be better to use LTC7001 with higher working voltage and also built in oscillator for static signal relaying.

    Regards,