STEVAL-ISA154V1 STMicroelectronics

STEVAL-ISA154V1 0.7 A step-down switching regulator evaluation board based on the L5980 Data brief Description 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 STEVAL- ISA154V1 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 Features 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 0.7 A DC output current output capacitor (16 V). The compensation 2.9 V to 18 V input voltage network on the evaluation board allows the use of Output voltage adjustable from 0.6 V to 16 V an MLCC as output filter to keep the loop stable. 250 kHz switching frequency, programmable The inductor saturation current and forward up to 1 MHz current of the Schottky diode are within the Internal soft-start and inhibit current limit values. The switching frequency on Low dropout operation: 100% duty cycle the board is set to 500 kHz by means of the R5 Zero-load current operation resistor connected to pin Fsw. Overcurrent and thermal protection VFQFPN8 (3 x 3 mm) package April 2014 DocID026204 Rev 1 1/4 www.st.com For further information contact your local STMicroelectronics sales office Schematic diagram STEVAL-ISA154V1 1 Schematic diagram Figure 1: STEVAL-ISA154V1 circuit schematic L1 15 H VIN = 3.3 V to 18 V Vout = 3.3 V VCC OUT 8 D1 INH SYNCH 2 3 STPS2L25U L5980 C2 GND 7 R1 4.99K 22 F FB C1 C6 5 6 4 C4 10nF 10 F 68 n F COMP FSW C3 3.3nF R3 180 R4 3.9K R5 100 K R2 1.1K C5 150 pF GSPG0904141630SG 2/4 DocID026204 Rev 1