The LM5118-Q1 widevoltage range Buck-Boost switching regulator controller features all of the functions necessary toimplement a high-performance, cost-efficient Buck-Boost regulator using a minimum of externalcomponents. The Buck-Boost topology maintains output voltage regulation when the input voltage iseither less than or greater than the output voltage, making it especially suitable for automotiveapplications. The LM5118-Q1operates as a buck regulator while the input voltage is sufficiently greater than the regulatedoutput voltage and gradually transitions to the buck-boost mode as the input voltage approaches theoutput. This dual-mode approach maintains regulation over a wide range of input voltages withoptimal conversion efficiency in the buck mode and a glitch-free output during mode transitions.This easy-to-use controller includes drivers for the high-side buck MOSFET and the low-side boostMOSFET. The regulators control method is based upon current mode control using an emulated currentramp. Emulated current mode control reduces noise sensitivity of the pulse-width modulationcircuit, allowing reliable control of the very small duty cycles necessary in high input voltageapplications. Additional protection features include current limit, thermal shutdown and an enableinput. The device is available in a power-enhanced, 20-pin HTSSOP package featuring an exposed dieattach pad to aid thermal dissipation.