General Description                                                                    

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 con-ditioning 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 ver-sion) 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 shut-down pin with an external RC circuit allowing the user to tailorthe 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-volt-age 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

Typical Performance Characteristics