L6986H Datasheet 38 V, 2 A synchronous step-down switching regulator with 30 A quiescent current Features 2 A DC output current 4 V to 38 V operating input voltage Low consumption mode or low noise mode 30 A I at light-load (LCM V = 3.3 V) Q OUT 8 A I Q-SHTDWN Adjustable f (250 kHz - 2 MHz) SW Fixed output voltage (3.3 V and 5 V) or adjustable from 0.85 V to V IN Embedded output voltage supervisor Synchronization Adjustable soft-start time Internal current limiting Overvoltage protection Output voltage sequencing Peak current mode architecture R = 180 m, R = 150 m DS(on) HS DS(on) LS Thermal shutdown Applications Product status link L6986H Designed for 12 V and 24 V buses Programmable logic controllers (PLCs) Decentralized intelligent nodes Sensors and low noise applications (LNM) Description The L6986H is a step-down monolithic switching regulator able to deliver up to 2 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 cycle operation. The wide input voltage range meets the specification for 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 maximizes the efficiency at light-load with controlled output voltage ripple. The low noise mode (LNM) makes the switching frequency constant and minimizes the output voltage ripple overload current range, meeting the low noise application specifications. The output voltage supervisor manages the reset phase for any digital load (C, FPGA). The RST open collector output can also implement output voltage sequencing during the power-up phase. The synchronous rectification, designed for high efficiency at medium - heavy load, and the high switching frequency capability make the size of the application compact. Pulse by pulse current sensing on both power elements implements an effective constant current protection. DS12905 - Rev 2 - February 2020 www.st.com For further information contact your local STMicroelectronics sales office.uC RST 4 1 SYNCH RST 15 16 VIN VIN VBIAS 2 13 VOUT VCC LX 14 10uH LX 5 FSW 10uF 1uF 240k L6986H 6 MLF 9 FB 3 SS/INH 75k 20uF 8 7 DELAY COMP EP SGND PGND PGND 470nF 68nF 10nF 330p 2.2p 82k 17 10 11 12 signal GND power GND GND L6986H Application schematic 1 Application schematic Figure 1. Application schematic DS12905 - Rev 2 page 2/68