Using the Motorola Phone Tools software users should be able to either sync their contacts with Outlook or similar program or directly export the contacts as CSV, which is what phb to csv conversion typically represents.
There is also a possibility for another phb to csv conversion but that is related to embroidery files where certain programs allows embroidery designs to be exported as CSV files. But that is very uncommon conversion used for very specific reasons.Open PHB file Open CSV file
Advanced version of the popular Embroidermodder
A utility for Motorola phones