Not only do integrated 48V drivers offer benefits such as reduced complexity, a comparison of size to traditional 12V gate driver implementations reveals interesting trade-offs.

Integrated Drivers: Integrated 48V drivers typically integrate the final drive stage MOSFETs and their gate drive circuitry into a single package. The package size and die cost of motor drivers increases significantly for lower RDS(on) (on-state resistance) values. Thus, due to the lower current requirements, 48V drivers can occupy a smaller board area for similar power capabilities compared to 12V gate driver plus external MOSFET implementations.

One limitation on shrinking the 48V driver package to take advantage of the smaller die size is the requirement that 48V signals must be physically separated from other signals by larger distances than 12V signals. These creepage and clearance specifications bound how small 48V driver packages can be, regardless of reduction in die size due to lower drive currents.

Gate Driver and External FETs: A traditional 12V gate driver combined with external MOSFETs, while potentially taking up more board space for a given RDS(on), allows for greater flexibility in selecting the preferred external FETs for the application, potentially achieving lower RDS(on) and better thermal performance. So designers must consider this in evaluating the benefits and drawbacks of converting from 12V to 48V.