Product Details

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[ National-Semiconductor ]

General DescriptionLBut

The LM2841 and LM2842 are PWM DC/DC buck (step-down) regulators. With a wide input range from 4.5V-42V, they are suitable for a wide range of applications such as power conditioning from unregulated sources. They feature a low RDSON (0.9Ω typical) internal switch for maximum efficiency (85% typical). Operating frequency is fixed at 550 kHz (X version) and 1.25 MHz (Y version) allowing the use of small external components while still being able to have low output voltage ripple. Soft-start can be implemented using the shutdown pin with an external RC circuit allowing the user to tailor the soft-start time to a specific application.
The LM2842 is optimized for up to 600 mA load currents while the LM2841 is optimized for up to 300 mA load current. Both have a 0.765V nominal feedback voltage.
Additional features include: thermal shutdown, VIN under-voltage lockout, and gate drive under-voltage lockout. The LM2841 and LM2842 are available in a low profile TSOT-6L package.

Features

■ Input voltage range of 4.5V to 42V
■ Output current options of 300 mA and 600 mA
■ Feedback pin voltage of 0.765V
■ 550 kHz (X) or 1.25 Mhz (Y) switching frequency
■ Low shutdown IQ, 16 µA typical
■ Short circuit protected
■ Internally compensated
■ Soft-start circuitry
■ Small overall solution size (TSOT-6L package)

Applications

■ Battery powered equipment
■ Industrial distributed power applications
■ Portable media players
■ Portable hand held instruments