STEVAL-ISA155V1 STMicroelectronics

STEVAL-ISA155V1 1 A constant current DC/DC converter evaluation board based on the L6902D Data brief Description The STEVAL-ISA155V1 product evaluation board integrates the L6902D step-down switching regulator with adjustable current limit, together with the external components required for a typical application. The input voltage of the board can range from 8 V up to 25 V due to the rated voltage of the input capacitor and the Schottky rectifier repetitive peak reverse voltage (both 25 V). The external resistor divider (R1 and R2) sets the output voltage of the application board to 3.3 V. A different output voltage can be regulated from 1.235 V up to 10 V according to the rated voltage of the output capacitor. A current limit of 1 A is programmed by the Features 100 m sense resistor (Rsense). The inductor Up to 1 A output current saturation current and the forward current of the Operating input voltage from 8 V to 25 V Schottky rectifier fit the current limit setting. Precise 3.3 V (2%) reference voltage 5% output current accuracy Output voltage adjustable from 1.235 V to 34 V 250 kHz internally fixed frequency Voltage feedforward Zero load current operation Adjustable current limit Protection against feedback disconnection Thermal shutdown RoHS compliant December 2017 DocID026426 Rev 2 1/4 www.st.com For further information contact your local STMicroelectronics sales office Schematic diagram STEVAL-ISA155V1 1 Schematic diagram Figure 1: STEVAL-ISA155V1 ciruit schematic VREF U1 L6902D VIN = 8V to 36V L1 Rsense 8 1 VOUT = 3.3V VCC VOUT 6 2 22uH 100m VREF CS+ 3 D1 R1 CS- STPS2L40U 5.6K 4 5 COMP FB GND C1 C4 7 10uF C2 22nF 50V 150uF 10V C3 220pF R2 R3 3.3K 5.1K GND GND. 2/4 DocID026426 Rev 2