LM2841 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – 300 mA/600 mA up to 42V Input Step-Down DC/DC Regulator in Thin SOT-23

LM2841
LM2842
September 2, 2009
300 mA/600 mA up to 42V Input Step-Down DC/DC
Regulator in Thin SOT-23
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
R_DSON (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 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, V_IN 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 I}_Q^{, 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 Application Circuit
30036702
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