STEVAL-ISA185V1 STMicroelectronics

STEVAL-ISA185V1 38 V, 0.5 A synchronous step-down switching regulator evaluation board based on A6985F3V3 Data brief Description The STEVAL-ISA185V1 is a product evaluation board based on the ST synchronous step-down switching regulator A6985F3V3, which can deliver up to 0.5 A and, with its 100% duty cycle ability to withstand cold crank events and wide input operating voltage range, renders the A6985F3V3 the ideal choice for battery-powered automotive systems. Synchronous rectification helps achieve higher efficiency at full load as well as application compactness, while high- frequency switching (programmable up to 2 MHz) helps to reduce the cost and size of power passive components while remaining outside the AM band. Features The device can operate in low consumption AECQ100 qualification mode (LCM) with a quiescent current of 30 A, 0.5 A DC output current hence ensuring the high efficiency under light 4 V to 38 V operating input voltage load condition required in typical car body Low consumption mode or low noise mode applications that are active during car parking. A Programmable ISKIP current low noise mode (LNM) can be selected to meet 30 A IQ at light load (LCM VIN = 12 V) the requirements of infotainment applications with 8 A IQ-SHTDWN forced PWM mode under all load conditions. Adjustable f (250 kHz - 2 MHz) SW The default board configuration is LCM active, 2 Fixed output voltage V = 3.3 V OUT MHz switching frequency, high I current and SKIP Embedded output voltage supervisor the switchover feature enabled, but all of these Synchronization settings can be easily changed so the user can Adjustable soft-start time evaluate different application scenarios. Internal current limiting Overvoltage protection Output voltage sequencing Peak current mode architecture RDS(on)HS = 360 m RDS(on)LS = 150 m Thermal shutdown RoHS compliant January 2016 DocID028905 Rev 1 1/4 www.st.com For further information contact your local STMicroelectronics sales office Schematic diagram STEVAL-ISA185V1 1 Schematic diagram Figure 1: STEVAL-ISA185V1 board schematic GSPG21012015DI1045 2/4 DocID028905 Rev 1 TTPP11 R1R111 10R10R RR55 NMNM TTPP22 RRSSTT SSSS//IINNHH R1R100 NMNM U1U1 AA66998855FF33VV33 TTPP33 RR66 1M1M TTPP44 4 1 VVOOUUTT SSYYNNCCHH SYNCH RST J3J3 VIN FLT 15 16 VIN VBIAS LL11 44..77uuHH 2 13 VCC LX J5J5 14 RR33 NMNM LX L1L1AA NMNM 5 FSW J2J2 RR11 00 6 CC77 NMNM MLF 9 FB 3 SS/INH RR88 110k110kCC88 68p68p RR99 NMNM RR77 0R0R 8 7 DELAY COMP ++ CC1111 C3C3 R2R2 R4R4 ++ CC44 11..22pp NMNM 56k56k EP SGND PGND PGND NMNM 470nF470nF C5C5 C6C6 17 10 11 12 J1J1 68nF68nF 10nF10nF signal GND TTPP77 PGND power GND GGNNDD J4J4 TTPP88 L3L3 TTPP55 LL22 44..77uuHH VIN FLT VVIINN MMPPZZ22001122SS222211AA VVIINN EEMMII TTPP66 PGND GGNNDD CC1133AA NMNM C1C166 44..77uuFF NMNM CC1313 CC11 10u10uFF 5050VV CC22 1uF1uF C1C155 44..77uuFF C1C144 44..77uuFF CC99 10u10uFF C1C100 NMNM