STEVAL-ISA188V1

STEVAL-ISA188V1 38 V, 1.5 A synchronous step-down switching regulator evaluation board based on A6986F3V3 Data brief Description The STEVAL-ISA188V1 is a product evaluation board based on the ST synchronous step-down switching regulator A6986F3V3, which can deliver up to 1.5 A and, with its 100% duty cycle ability to withstand cold crank events and wide input operating voltage range, represents 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 reduce the cost and size of power passive components while remaining outside the AM band. The device can operate in low consumption mode (LCM), with a Features quiescent current of 30 A that ensures high efficiency under light load, which is a requirement AECQ100 qualification in typical car body applications that are active 1.5 A DC output current when a car is parked. A low noise mode (LNM) 4 V to 38 V operating input voltage can be selected to meet the requirements of Low consumption mode or low noise mode infotainment applications with forced PWM mode Programmable ISKIP current under all load conditions. The default board 30 A IQ at light load (LCM VIN = 12 V) configuration is LCM active, 500 kHz switching 8 A IQ-SHTDWN frequency, high ISKIP current and the switchover Adjustable f (250 kHz - 2 MHz) SW feature enabled, but all of these settings can be Fixed output voltage V = 3.3 V OUT easily changed so the user can evaluate different Embedded output voltage supervisor application scenarios. Synchronization Adjustable soft-start time Internal current limiting Overvoltage protection Output voltage sequencing Peak current mode architecture RDS(on)HS = 180 m RDS(on)LS = 150 m Thermal shutdown RoHS compliant February 2016 DocID028953 Rev 1 1/4 www.st.com For further information contact your local STMicroelectronics sales office Schematic diagram STEVAL-ISA188V1 1 Schematic diagram Figure 1: STEVAL-ISA188V1 schematic circuit GSPG02022016DI1510 2/4 DocID028953 Rev 1 TTPP11 R1R111 10R10R RR55 NMNM TTPP22 RRSSTT SSSS//IINNHH R1R100 NMNM U1U1 AA66998866FF33VV33 TTPP33 RR66 1M1M TTPP44 4 1 VVOOUUTT SSYYNNCCHH SYNCH RST J3J3 VIN FLT 15 16 VIN VBIAS LL11 66..88uuHH 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 75k75k CC88 220p220p RR99 NMNM RR77 0R0R 8 7 DELAY COMP ++ CC1111 C3C3 R2R2 R4R4 ++ CC44 22..22pp NMNM 0R0R 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 CC1133 CC11 10u10uFF 5050VV CC22 1uF1uF C1C155 44..77uuFF C1C144 44..77uuFF CC99 10u10uFF C1C100 10u10uFF