LM2672M-12 National Semiconductor, LM2672M-12 Datasheet - Page 13
![DC/DC Converter IC](/photos/18/97/189768/3778330_sml.jpg)
LM2672M-12
Manufacturer Part Number
LM2672M-12
Description
DC/DC Converter IC
Manufacturer
National Semiconductor
Specifications of LM2672M-12
Input Voltage
40V
Output Current
1A
Output Voltage
12V
No. Of Pins
8
Mounting Type
Surface Mount
Voltage Regulator Type
Switching
Output Current Max
1A
Peak Reflow Compatible (260 C)
No
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LM2672M-12/NOPB
Manufacturer:
National Semiconductor
Quantity:
135
Company:
Part Number:
LM2672M-12/NOPB
Manufacturer:
NS
Quantity:
10
where:
I
t
V
V
V
V
If this feature is not desired, leave this pin open.
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 kΩ resistor and a 100 pF capacitor are suitable
values.
SS
SS
SSTH
OUT
SCHOTTKY
IN
LM2672 Series Buck Regulator Design Procedure (Fixed Output)
INDUCTOR VALUE SELECTION GUIDES (For
Continuous Mode Operation)
= Soft-Start Current :4.5 µA typical.
= Soft-Start Time :Selected.
= Input Voltage :Selected.
= Output Voltage :Selected.
PROCEDURE (Fixed Output Voltage Version)
= Soft-Start Threshold Voltage :0.63V typical.
= Schottky Diode Voltage Drop :0.4V typical.
FIGURE 4. LM2672-3.3
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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 5. LM2672-5.0
(Continued)
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01293430