STMicroelectronics L7987

The L7987 device is a step-down monolithic switching regulator able to deliver up to 2A DC output current. The output voltage adjustability ranges from 0.8 V to V_IN. 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 V_BIAS 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.

Key features

• 2A DC output current
• 4.5 V to 61 V operating input voltage
• R_DS(On) = 300 mΩ typ.
• Adjustable f_SW (250 kHz - 1.5 MHz)

Additional features

• Low IQ-SHD (11 μA typ. from VIN )
• Low IQ (1 mA typ. - V_IN 24 V - V_OUT 3.3 V)
• Output voltage adjustable from 0.8 V to V_IN
• Synchronization
• Adjustable soft-start time
• Adjustable current limitation
• Low dropout operation (12 μs max.)
• V_BIAS 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

Applications

• Designed for 24 V bus
• Fail safe tolerant system
• Programmable logic controllers (PLCs)

Available tools

STEVAL-ISA198V1:

2 A step down DC - DC switching regulator (VIN = 4.5 V to 60 V) based on the L7987L

The STEVAL-ISA198V1 product evaluation board is a step-down switching power supply based on the L7987L regulator in an HTSSOP16 package. The output voltage can be set starting from 0.8 V. Low drop-out operation, due to the advanced integrated switch management, can be achieved. The L7987L is a 61 V, 2 A step-down asynchronous switching regulator with embedded power MOSFET capable of delivering up to 2 A of current, depending on the application conditions.

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