We are using the LTC3556 in our new design and would like to know if it is possible to disable any of the buck converters without using the I²C configuration. It is possible that one of the converters will not be used in the system, and we would like to know the best practices to terminate the converter related pins.
Could you please clarify what happens to the output of the buck converters if VINx is either floating or tied to ground. Could this be a way to disable the converters when unused on the system?
Thanks in advance!
The best way to do this to keep PGOODALL happy is connect VINx and FBx to VOUT and float the SW pin for the regulator that is not going to be used. If I2C is used after the power up then the buck can be disabled and save on some Iq current, ~20uA I think.
Hi, Marty, thanks for your response.