The PT6441N from Texas Instruments is a non-isolated point-of-load DC-DC converter module with 1 output at 3.3 V and 6 A, accepting a 4.5 V to 5.5 V input.
The PT6441C from Texas Instruments is a non-isolated point-of-load DC-DC converter module with 1 output at 3.3 V and 6 A, accepting a 4.5 V to 5.5 V input.