data brief for further information contact your local stmicroelectronics sales office. july 2009 doc id 15973 rev 1 1/4 4 STEVAL-ISA047V2 1.5 a / 3.3 v step-down dc-dc converter demonstration board ba sed on the st1s03a features step-down current mode pwm (1.5 mhz) dc-dc converter 2% dc output voltage tolerance internal soft-start for start-up current limitation and power on delay of 50-100 s typical efficiency: > 85% inhibit function 1.5 a output current capability not switching quiescent current: max 1.5 ma (overtemperature range) switch v ds : max 200 mv @ i sw = 750 ma uses tiny capacitors and inductors rohs compliant description this demonstration board is based on the st1s03a, an adjustable current mode pwm step-down dc-dc converter with internal 1.5 a power switch, packaged in a 6-lead dfn 3x3 mm. it's a complete 1.5 a swit ching regulator with its internal compensation eliminating additional component. the constant frequency, current mode, pwm architecture and stable operation with ceramic capacitors results in low, predictable output ripple. however, in order to maximize the power conversion efficiency with light load, the regulator reduces automatically the switching frequency when the output load becomes less than 250 ma typically. STEVAL-ISA047V2 www.st.com
circuit schematic STEVAL-ISA047V2 2/4 doc id 15973 rev 1 1 circuit schematic figure 1. schematic diagram
STEVAL-ISA047V2 revision history doc id 15973 rev 1 3/4 2 revision history table 1. document revision history date revision changes 01-jul-2009 1 initial release.
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