The B5973D is a step down monolithic power switching regulator with a minimum switch current limit of 2.25 A so it is able to deliver up to 2 A DC current to the load depending on the application conditions. The output voltage can be set from 1.235 V to 35 V. The high current level is also achieved thanks to an SO8 package with exposed frame, that allows to reduce the Rth(JA) down to approximately 40 C/W. The device uses an internal P-channel DMOS transistor (with a typical RDSon of 250 m) as switching element to minimize the size of the external components. An internal oscillator fixes the switching frequency at 250 kHz. Having a minimum input voltage of 4V only, it is particularly suitable for 5 V bus. Pulse by pulse current limit with the internal frequency modulation offers an effective constant current short circuit protection. Pulse by pulse current limit with the internal frequency modulation offers an effective constant current short circuit protection.