data brief for further information contact your local stmicroelectronics sales office. december 2011 doc id 022615 rev 1 1/4 4 STEVAL-ISA091V1 2 a step-down switching power supply demonstration board based on the l7980 (qfn) features 2 a dc output current 4.5 v to 28 v input voltage output voltage: 3.3 v (adjustable from 0.6 v) 250 khz switching frequency, programmable up to 1 mhz internal soft-start and enable low dropout operation: 100% duty cycle voltage feed-forward zero load current operation overcurrent and thermal protection rohs compliant description the STEVAL-ISA091V1 is step-down switching power supply based on stmicroelectronics? l7980 switching regulator in a qfn package. the l7980 features an embedded power mosfet and is capable of delivering up to 2 a of current to the load, depending on the application conditions. the input voltage can range from 4.5 v to 28 v, while the output voltage can be set from 0.6 v to v in . requiring a minimum number of external components, the device includes an internal 250 khz switching frequency oscillator that can be externally adjusted up to 1 mhz. STEVAL-ISA091V1 www.st.com
schematic diagram STEVAL-ISA091V1 2/4 doc id 022615 rev 1 1 schematic diagram figure 1. STEVAL-ISA091V1 circuit schematic " . 7 * / 7 $ $ 7 0 6 5 7 0 6 5 7 7 7 7 $ o ' & |