The LM5118 Wide Voltage Range Buck-Boost Switch Regulator controller has all the features necessary to achieve a high performance, cost efficient Buck-Boost regulator using a minimum of external components. The BuckBoost topology keeps the output voltage tuned when the input voltage is less than or greater than the output voltage, making it particularly suitable for automotive applications.

     LM5118 works as a step-down voltage regulator when the input voltage is sufficiently greater than the regulated output voltage, and gradually transitions to step-up mode as the input voltage approaches the output. This dual-mode approach maintains a wide range of input voltage regulation and has optimal conversion efficiency in step-down mode, with trouble-free output during mode conversion. This easy to use controller includes a driver for a high side step-down MOSFET and a low side step-up MOSFET. The control method of the regulator is based on the current mode control and adopts the analog current ramp.

     Simulation current mode control reduces the noise sensitivity of pulse width modulation circuits, allowing reliable control of the very small duty cycle required in high input voltage applications. Other protection features include current limit, heat off and enable input. The device comes in a power-enhanced, 20-pin HTSSOP package with an exposed die attachment pad to aid in heat dissipation.