november 2013 docid8827 rev 3 1/30 AN1517 application note designing with the steval-isa0 89v1 high efficiency dc-dc converter by massimili ano merisio introduction the l5972d device is a step-down monolithic power switching regulator capable of delivering up to 2 a at output voltages from 1.235 v to 35 v. the operating input voltage ranges from 4.4 v to 36 v. the device has been designed using bcdv technology and the power switching element is implemented throug h a p-channel dmos transistor. it does not require a bootstrap capacitor, and the duty cycle can range up to 100%. an internal oscillator fixes the switching fr equency at 250 khz. this mi nimizes the lc output filter. pulse-by-pulse and frequency foldback overcu rrent protection offe r effective protection against short-circuit. other features are volt age feed-forward, protection against feedback disconnection, and thermal shutdown. the devic e is housed in a thermally improved so-8 package (with 4 pins connected to gnd so that the thermal resistance junction to ambient is reduced to approximately one-half compared with a standard so-8 package. figure 1. demonstration board steval-isa089v1 (so-8) board dimensions: 34 x 43 mm figure 2. package figure 3. pin connection so-8 2 8 7 * 1 ' * 1 ' & |