LM2672N-12 National Semiconductor, LM2672N-12 Datasheet - Page 11

• Manufacturer Part Number: LM2672N-12
• Description: Voltage Regulator IC
• Manufacturer: National Semiconductor

Specifications of LM2672N-12

• Output Current: 1A
• Output Voltage: 12V
• No. Of Pins: 8
• Peak Reflow Compatible (260 C): No
• Leaded Process Compatible: No
• Mounting Type: Through Hole
• Package / Case: 8 Lead
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

7. Frequency Synchronization (optional)
The LM2672 (oscillator) can be synchronized to run with an
external oscillator, using the sync pin (pin 3). By doing so, the
LM2672 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 k
capacitor are suitable values.
LM2672 Series Buck Regulator Design Procedure (Fixed Output)
INDUCTOR VALUE SELECTION GUIDES (For Continuous Mode Operation)
PROCEDURE (Fixed Output Voltage Version)
FIGURE 4. LM2672-3.3
FIGURE 5. LM2672-5.0
resistor and a 100 pF
DS012934-30
DS012934-29
11
7. Frequency Synchronization (optional)
For all applications, use a 1 k
for the RC filter.
EXAMPLE (Fixed Output Voltage Version)
FIGURE 7. LM2672-ADJ
FIGURE 6. LM2672-12
resistor and a 100 pF capacitor
(Continued)
DS012934-32
DS012934-31
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