A7987TR STMicroelectronics

A7987 Datasheet 61 V, 3 A asynchronous step-down switching regulator with adjustable current limitation for automotive Features 3 A DC output current 4.5 V to 61 V operating input voltage Adjustable f (250 kHz to 1.5 MHz) sw Output voltage adjustable from 0.8 V to V IN Synchronization Adjustable soft-start time Adjustable current limitation VBIAS improves efficiency at light load PGOOD open collector output Digital frequency fold-back in short-circuit Auto-recovery thermal shutdown Qualified following AEC-Q100 requirements Applications Designed for 24 V automotive battery systems Industrial and commercial vehicles Description The A7987 is a step-down monolithic switching regulator that can deliver up to 3 A Product status link DC. The adjustable output voltage ranges from 0.8 V to V . The wide input voltage IN range and the almost 100% duty cycle capability meet the fail-safe specifications for A7987 automotive systems. The embedded switch-over feature on the VBIAS pin maximizes efficiency at light load. The adjustable current limitation, designed to select the inductor RMS current in accordance with the nominal output current, and the high switching frequency capability make the size of the application compact. Pulse-by- pulse current sensing with digital frequency fold-back implements an effective constant current protection over the different application conditions. The peak current fold-back decreases the stress of the power components in heavy short-circuit conditions. The PGOOD open collector output can also implement the output voltage sequencing during the power-up phase. Multiple devices can be synchronized sharing the SYNCH pin to prevent beating noise for low noise requirements such as in infotainment applications. DS12928 - Rev 3 - September 2020 www.st.com For further information contact your local STMicroelectronics sales office.A7987 Application schematic 1 Application schematic Figure 1. Application schematic R1 PGOOD U1 7 12 SYNCH PGOOD 2 1 VOUT VIN VIN VBIAS 3 VIN 15 BOOT C7 A7987 4 VCC 13 5 LX L1 EN 14 LX 6 R5 C8 SS 9 10 FB 100 V 100 V FSW 11 R6 C9 R7 8 ILIM TP GND COMP C11 17 16 D1 C10 C1 C4 R11 C5 GND GND DS12928 - Rev 3 page 2/36