Two 300 mA outputs in an 8-SOIC — what that buys the board
Each of the two independent elements sinks up to 300 mA, which is enough to pull in a standard automotive relay or drive a bank of LEDs without an external transistor.
If you are qualifying a second source for supply resilience, the functional equivalent search should target other dual peripheral drivers in 8-SOIC with similar output current — the SN75477D is not pin-compatible with octal transceivers or bus buffers, so don't waste time on those.
Package and footprint — the scorch mark tells you it's an 8-SOIC
If you are replacing a blown part on a board, the scorch mark on the PCB will align with that 8-pin SOIC pattern — measure the width to confirm it's the narrow version, not the wide 7.5 mm body. The shipping medium is Tube, not Tape & Reel, so factor in hand-placement or tube-feeder handling if you are running high-volume pick-and-place.
