STEVAL-ISA154V1

STEVAL-ISA154V1 0.7 A step-down switching regulator evaluation board based on the L5980 Data brief Description Features • • • • • • • • • 0.7 A DC output current 2.9 V to 18 V input voltage Output voltage adjustable from 0.6 V to 16 V 250 kHz switching frequency, programmable up to 1 MHz Internal soft-start and inhibit Low dropout operation: 100% duty cycle Zero-load current operation Overcurrent and thermal protection VFQFPN8 (3 x 3 mm) package April 2014 The STEVAL-ISA154V1 product evaluation board provides the design engineer with a fully functional step-down switching regulator with an output current of up to 0.7 A. The STEVALISA154V1 integrates STMicroelectronics' L5980 step-down switching regulator together with all the external components required for a typical application. The rated voltage of the input capacitor and the Schottky diode rectifier repetitive peak reverse voltage are both 25 V, making the board capable of covering the entire 2.9 V - 18 V input voltage range of the L5980 device. The board features an external resistor divider (R1 and R2) designed for an output voltage of 3.3 V. The output voltage can be set to a level from 0.6 V up to the rated voltage of the output capacitor (16 V). The compensation network on the evaluation board allows the use of an MLCC as output filter to keep the loop stable. The inductor saturation current and forward current of the Schottky diode are within the current limit values. The switching frequency on the board is set to 500 kHz by means of the R5 resistor connected to pin Fsw. DocID026204 Rev 1 For further information contact your local STMicroelectronics sales office 1/4 www.st.com Schematic diagram 1 STEVAL-ISA154V1 Schematic diagram Figure 1: STEVAL-ISA154V1 circuit schematic VIN = 3.3 V to 18 V OUT VCC L1 15 µH Vout = 3.3 V 8 INH 2 3 GND 7 C1 10 µF C6 68 n F SYNCH 6 4 5 D1 STPS 2L25 U L5980 FB 22 µF C4 10nF FSW R5 100 K COMP R4 3.9K R3 180 R2 1.1K C5 150 pF GSPG0904141630SG 2/4 C2 R1 4.99 K DocID026204 Rev 1 C3 3.3 nF STEVAL-ISA154V1 2 Revision history Revision history Table 1: Document revision history Data Revision 15-Apr-2014 1 DocID026204 Rev 1 Changes Initial release 3/4 STEVAL-ISA154V1 Please Read Carefully Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. 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