LM2672EP datasheet(13/25 Pages) NSC

Part #	LM2672EP

Description	Enhanced Plastic SIMPLE SWITCHER Power Converter High Efficiency 1A Step-Down Voltage Regulator with Features

PDF	25 Pages

Scroll/Zoom	100%

Manufacturer	NSC [National Semiconductor (TI)]

Direct Link	http://www.national.com

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13 / 25 page

LM2672EP Series Buck Regulator Design Procedure (Fixed Output)

(Continued)

PROCEDURE (Fixed Output Voltage Version)

EXAMPLE (Fixed Output Voltage Version)

7. Frequency Synchronization (optional)

The LM2672EP (oscillator) can be synchronized to run with an

external oscillator, using the sync pin (pin 3). By doing so, the

LM2672EP can be operated at higher frequencies than the

standard frequency of 260 kHz. This allows for a reduction in

the size of the inductor and output capacitor.

As shown in the drawing below, a signal applied to a RC filter at

the sync pin causes the device to synchronize to the frequency

of that signal. For a signal with a peak-to-peak amplitude of 3V

or greater,a1k

Ω resistor and a 100 pF capacitor are suitable

values.

7. Frequency Synchronization (optional)

For all applications, usea1k

Ω resistor and a 100 pF capacitor

for the RC filter.

Inductor Value Selection Guides (For Continuous Mode Operation)

20097829

FIGURE 4. LM2672-3.3EP

20097830

FIGURE 5. LM2672-5.0EP

20097831

FIGURE 6. LM2672-12EP

20097832

FIGURE 7. LM2672-ADJEP

LM2672EP Datasheet(PDF) 13 Page - National Semiconductor (TI)