LM2672MX-ADJEP NSC [National Semiconductor], LM2672MX-ADJEP Datasheet - Page 13

• Manufacturer Part Number: LM2672MX-ADJEP
• Description: Enhanced Plastic SIMPLE SWITCHER Power Converter High Efficiency 1A Step-Down Voltage Regulator with Features
• Manufacturer: NSC [National Semiconductor]

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, a 1 kΩ resistor and a 100 pF capacitor are suitable
values.
LM2672EP Series Buck Regulator Design Procedure (Fixed Output)
Inductor Value Selection Guides
(Continued)
PROCEDURE (Fixed Output Voltage Version)
FIGURE 4. LM2672-3.3EP
FIGURE 5. LM2672-5.0EP
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20097829
(For Continuous Mode Operation)
13
7. Frequency Synchronization (optional)
For all applications, use a 1 kΩ resistor and a 100 pF capacitor
for the RC filter.
EXAMPLE (Fixed Output Voltage Version)
FIGURE 7. LM2672-ADJEP
FIGURE 6. LM2672-12EP
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