I want the circuit to take a TTL PWM signal in and produce 12V hi side switching out. It doesn't need to supply the TTL PWM signal just pass it through to the output at a 12V level. It must be capable of a switching speed of at least 100k Hz while passing 50A (maximum rating) of current. It doesn't need to supply the 50A, we have power supplies that can do that. The input PWM signal will be at either 20%, 50% or 80% and the output must maintain this Duty Cycle. Smaller than 50A is acceptable if the circuits can work in parallel to add up to achieve a 50A output. Preferably, I want an already fabricated circuit board, a pre-constructed box or at the very least a circuit board layout with schematic. Do you know of a company that can assist me?