L7987 Description
The L7987 device is a step-down monolithic switching regulator able to deliver up to 3 A DC. The output voltage adjustability ranges from 0.8 V to VIN. The wide input voltage range and the 100% duty cycle capability meet the fail safe specifications for industrial systems. The embedded switchover feature on the VBIAS pin maximizes the efficiency at light load. The adjustable current limitation, designed to select the inductor RMS current accordingly 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 foldback implements an effective constant current protection over the different application conditions. The peak current foldback decreases the stress of the power components in heavy short-circuit condition. The PGOOD open collector output can also implement output voltage sequencing during the power-up phase. Multiple devices can be synchronized sharing the SYNCH pin to prevent beating noise in low noise applications like sensors with A/D conversion.
L7987 Features
3 A DC output current
4.5 V to 61 V operating input voltage
RDS,ON = 250 mΩ typ.
Adjustable fSW (250 kHz - 1.5 MHz)
Low IQ-SHD (11 μA typ. from VIN)
Low IQ (1 mA typ. - VIN 24 V - VOUT 3.3 V)
Output voltage adjustable from 0.8 V to VIN
Synchronization
Adjustable soft-start time
Adjustable current limitation
Low dropout operation (12 μs max.)
VBIAS improves efficiency at light load
PGOOD open collector output
Output voltage sequencing
Digital frequency foldback in short-circuit
Peak current foldback in short-circuit
Auto-recovery thermal shutdown
L7987 Applications
Designed for 24 V bus
Fail safe tolerant system
Programmable logic controllers (PLCs)
5G Communication
Electrification of automobile
Industrial 4.0
