649A DC Power Unit
The Definity 649A DC Power Unit converts a-48 VDC input into outputs of -48 VDC at 10A, +5 VDC, and -5VDC at 6A. The outputs are distributed to circuit pack slots in the carriers. Only one 649A converter is required per carrier except for SN carriers. SN carriers require 2 converters; 1 on each end. The use of the 649A also allows an increase in the number of terminals supported per carrier. The 649A is not compatible with the 644A or the 645B power converters and is used in Release 6 systems.