The A5973AD is a step-down monolithic power switching regulator with a minimum switch current limit of 1.8 A, so it is able to deliver up to 1.5 A DC current to the load depending on the application conditions. The output voltage can be set from 1.235 V to VIN. The high current level is also achieved thanks to an HSOP8 package with an 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 RDS(on)of 250 mΩ) as a switching element to minimize the size of the external components. An internal oscillator fixes the switching frequency at 500 kHz. Having a minimum input voltage of 4 V only it fits the automotive applications requiring the device operation even in cold crank conditions. A pulse-by-pulse current limit with the internal frequency modulation offers an effective constant current short-circuit protection.