A6985F STMicroelectronics

A6985F Automotive 38 V, 500 mA synchronous step-down switching regulator with 30 A quiescent current Datasheet - production data Description The A6985F automotive grade device is a step- down monolithic switching regulator able to deliver up to 0.5 A DC. The output voltage adjustability ranges from 0.85 V to VIN. The 100% duty cycle capability and the wide input voltage range meet the cold crank and load dump HTSSOP16 (R = 40 C/W) TH specifications for automotive systems. The Low Consumption Mode (LCM) is designed for applications active during car parking, so it Features maximizes the efficiency at light-load with controlled output voltage ripple. The Low Noise AEC-Q100 qualified Mode (LNM) makes the switching frequency 0.5 A DC output current constant and minimizes the output voltage ripple overload current range, meeting the low noise 4 V to 38 V operating input voltage application specification like car audio. The output Low consumption mode or low noise mode voltage supervisor manages the reset phase for 30 A I at light-load (LCM V = 3.3 V) any digital load (C, FPGA). The RST open Q OUT collector output can also implement output 8 A I Q-SHTDWN voltage sequencing during the power-up phase. Fixed output voltage (3.3 V and 5 V) or The synchronous rectification, designed for high adjustable from 0.85 V to V IN efficiency at medium - heavy load, and the high Adjustable f (250 kHz - 2 MHz) switching frequency capability make the size of SW the application compact. Pulse by pulse current Embedded output voltage supervisor sensing on both power elements implements an Synchronization effective constant current protection. Adjustable soft-start time Internal current limiting Overvoltage protection Output voltage sequencing Peak current mode architecture R = 360 m , R = 150 m DSON HS DSON LS Thermal shutdown Applications Designed for automotive systems Battery powered applications Car body applications (LCM) Car audio and low noise applications (LNM) August 2020 DocID027738 Rev 7 1/83 This is information on a product in full production. www.st.comContents A6985F Contents 1 Application schematic . 5 2 Pin settings 6 2.1 Pin connection 6 2.2 Pin description 6 2.3 Maximum ratings 7 2.4 Thermal data . 8 2.5 ESD protection 8 3 Electrical characteristics . 9 4 Datasheet parameters over the temperature range . 14 5 Functional description 15 5.1 Power supply and voltage reference 16 Switchover feature . 16 5.2 Voltages monitor 16 5.3 Soft-start and inhibit . 17 5.3.1 Ratiometric startup . 23 5.3.2 Output voltage sequencing 25 5.4 Error amplifier 25 5.5 Output voltage line regulation 26 5.6 Output voltage load regulation . 26 5.7 High-side switch resistance vs. input voltage 27 5.8 Light-load operation . 27 5.8.1 Low noise mode (LNM) . 27 5.8.2 Low consumption mode (LCM) . 28 5.8.3 Quiescent current in LCM with switchover . 34 5.9 Switchover feature 36 5.9.1 LCM 36 5.9.2 LNM 36 5.10 Overcurrent protection . 36 OCP and switchover feature . 39 2/83 DocID027738 Rev 7