STEVAL-ISA198V1 STMicroelectronics

S T E VA L - I S A 1 9 8 V 1 2 A step down DC - DC switching regulator (VIN = 4.5 V to 60 V) based on the L7987L Data brief Description The STEVAL-ISA198V1 product evaluation board is a step-down switching power supply based on the L7987L regulator in an HTSSOP16 package. The output voltage can be set starting from 0.8 V. Low drop-out operation, due to the advanced integrated switch management, can be achieved. The L7987L is a 61 V, 2 A step-down asynchronous switching regulator with embedded power MOSFET capable of delivering up to 2 A of current, depending on the application conditions. The embedded switch-over feature on the V BIAS pin and the light load management (pulse skipping) help maximize power conversion efficiency across the entire load range. The soft-start, current limit threshold and switching frequency are adjustable for application Features optimization. 4.5 V to 60 V input voltage The device includes an internal 250 kHz oscillator Step-down (buck) conversion that can be externally adjusted up to 1.5 MHz 5 V output voltage (VIN > 6 V) two L7987L regulators can be synchronized in a Up to 2 A DC output current 180 out-of-phase configuration for reduced total 500 kHz switching frequency input RMS current. 5 ms programmed soft-start Compliant with ceramic output capacitors 180 out of phase synchronization available Auto recovery overcurrent and thermal protection RoHS compliant November 2016 DocID030001 Rev 1 1/4 www.st.com For further information contact your local STMicroelectronics sales office Schematic diagram STEVAL-ISA198V1 1 Schematic diagram Figure 1: STEVAL-ISA198V1 circuit schematic GSPG1310161600SG 2/4 DocID030001 Rev 1 IOCP = 3 A R1 NM TP1 Tss = 5.3 ms PGOOD Fsw = 500 kHz U1 TP2 R2 100k TP4 7 12 VOUT SYNCH SYNCH PGOOD TP3 J2 2 1 VIN VIN VBIAS 3 VIN 15 R4 BOOT 0 J1 VOUT = 5 V 4 C7 VCC J3 L7987L IOUT,MAX = 2 A TP5 5 13 100nF EN L1 15uH EN LX Fbw = 60 kHz 14 LX 6 Ph = 60 deg SS R5 910 C8 680pF 9 FB 10 FSW 10k R6 C9 6.8nF R7 68k 11 8 ILIM COMP EP GND C11 68pF 17 16 R8 D1 C10 R9 STPS2L60UF + 27k R10 R11 33nF 47k NM 13k signal GND TP6 TP7 power GND GND GND C1 4.7uF 100V C2 4.7uF 100V C3 1uF 100V C4 1uF 100V C5 47uF C6 N.M. C12 N.M.