L6986F 38 V, 1.5 A synchronous step-down switching regulator with 30 A quiescent current Datasheet - production data Description The L6986F is a step-down monolithic switching regulator able to deliver up to 1.5 A DC. The output voltage adjustability ranges from 0.85 V to VIN. Thanks to the P-channel MOSFET high-side power element, the device features 100% duty HTSSOP16 (R = 40 C/W) cycle operation. The wide input voltage range TH meet the 5 V, 12 V and 24 V power supplies. The Low Consumption Mode (LCM) is designed for applications active during idle mode, so it Features maximizes the efficiency at light-load with controlled output voltage ripple. The Low Noise 1.5 A DC output current Mode (LNM) makes the switching frequency 4 V to 38 V operating input voltage constant and minimizes the output voltage ripple Low consumption mode or low noise mode overload current range, meeting the low noise application specification. The output voltage 30 A I at light-load (LCM V = 3.3 V) Q OUT supervisor manages the reset phase for any 8 A I Q-SHTDWN digital load (C, FPGA). The RST open collector Adjustable f (250 kHz - 2 MHz) SW output can also implement output voltage sequencing during the power-up phase. The Output voltage adjustable from 0.85 V to V IN synchronous rectification, designed for high Embedded output voltage supervisor efficiency at medium - heavy load, and the high Synchronization switching frequency capability make the size of the application compact. Pulse by pulse current Adjustable soft-start time sensing on both power elements implements an Internal current limiting effective constant current protection. Overvoltage protection Output voltage sequencing Peak current mode architecture R = 180 m, R = 150 m DSON HS DSON LS Thermal shutdown Applications Designed for 12 V and 24 V buses Programmable logic controllers (PLCs) Decentralized intelligent nodes Sensors and low noise applications (LNM) February 2016 DocID027843 Rev 2 1/64 This is information on a product in full production. www.st.comContents L6986F Contents 1 Application schematic . 4 2 Pin settings 5 2.1 Pin connection 5 2.2 Pin description 5 2.3 Maximum ratings 6 2.4 Thermal data . 7 2.5 ESD protection 7 3 Electrical characteristics . 8 4 Functional description 12 4.1 Power supply and voltage reference 13 Switchover feature . 13 4.2 Voltages monitor 13 4.3 Soft-start and inhibit . 14 4.3.1 Ratiometric startup . 20 4.3.2 Output voltage sequencing 22 4.4 Error amplifier 22 4.5 Light-load operation . 23 4.5.1 Low noise mode (LNM) . 23 4.5.2 Low consumption mode (LCM) . 23 4.6 Switchover feature 29 4.6.1 LCM 29 4.6.2 LNM 29 4.7 Overcurrent protection . 29 OCP and switchover feature . 31 4.8 Overvoltage protection . 33 4.9 Thermal shutdown 34 2/64 DocID027843 Rev 2