L4960 STMicroelectronics

L4960 2.5A POWER SWITCHING REGULATOR 2.5A OUTPUT CURRENT 5.1V TO 40V OPUTPUT VOLTAGE RANGE PRECISE ( 2%) ON-CHIP REFERENCE HIGH SWITCHING FREQUENCY VERY HIGH EFFICIENCY (UP TO 90%) VERY FEW EXTERNAL COMPONENTS HEPTAWATT SOFT START INTERNAL LIMITING CURRENT ORDERING NUMBERS: L4960 (Vertical) THERMAL SHUTDOWN L4960H (Horizontal) DESCRIPTION TheL4960 is mountedina Heptawattplastic power The L4960 is a monolithic power switching regula- package and requires very few external compo- tor delivering 2.5A at a voltage variable from 5V to nents. 40V in step down configuration. Efficient operation at switching frequencies up to Features of the device include current limiting, soft 150KHz allows a reduction in the size and cost of start, thermal protection and 0 to 100% duty cycle external filter components. for continuous operation mode. BLOCK DIAGRAM June 2000 1/16L4960 PIN CONNECTION (Top view) ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit V Input voltage 50 V 1 V -V Input to output voltage difference 50 V 1 7 V Negative output DC voltage -1 V 7 Negative output peak voltage at t = 0.1s f = 100KHz -5 V V3,V6 Voltage at pin 3 and 6 5.5 V V Voltage at pin 2 7V 2 I Pin 3 sink current 1 mA 3 I Pin 5 source current 20 mA 5 P Power dissipation at T 90C15W tot case T,T Junction and storage temperature -40 to 150 C j stg PIN FUNCTIONS FUNCTION N NAME 1 SUPPLY VOLTAGE Unregulated voltage input. An internal regulator powers the internal logic. 2 FEEDBACK INPUT The feedback terminal of the regulation loop. The output is connected directly to this terminal for 5.1V operation it is connected via a divider for higher voltages. 3 FREQUENCY A series RC network connected between this terminal and COMPENSATION ground determines the regulation loop gain characteristics. 4 GROUND Common ground terminal. 5 OSCILLATOR A parallel RC network connected to this terminal determines the switching frequency. 6 SOFT START Soft start time constant. A capacitor is connected between this terminal and ground to define the soft start time constant. This capacitor also determines the average short circuit output current. 7 OUTPUT Regulator output. 2/16