LM2672M-12 National Semiconductor, LM2672M-12 Datasheet - Page 10

• 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

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To simplify the buck regulator design procedure, National
Semiconductor is making available computer design software to
be used with the SIMPLE SWITCHER line of switching
regulators. LM267X Made Simple version 1.0 is available on
Windows
Given:
Test Circuit and Layout Guidelines
C
C
D1 - 3.3A, 50V Schottky Rectifier, IR 30WQ05F
L1 - 68 µH Sumida #RCR110D-680L
R1 - 1.5 kΩ, 1%
C
For a 5V output, select R2 to be 4.75 kΩ, 1%
where V
Use a 1% resistor for best stability.
LM2672 Series Buck Regulator
Design Procedure (Fixed Output)
V
V
I
LOAD
IN
OUT
B
OUT
IN
- 0.01 µF, 50V Ceramic
- 22 µF, 50V Tantalum, Sprague “199D Series”
(max) = Maximum DC Input Voltage
- 47 µF, 25V Tantalum, Sprague “595D Series”
(max) = Maximum Load Current
= Regulated Output Voltage (3.3V, 5V, or 12V)
PROCEDURE (Fixed Output Voltage Version)
®
REF
3.1, NT, or 95 operating systems.
= 1.21V
FIGURE 3. Standard Test Circuits and Layout Guides
Adjustable Output Voltage Versions
(Continued)
10
Given:
V
V
I
LOAD
OUT
IN
(max) = 12V
(max) = 1A
= 5V
EXAMPLE (Fixed Output Voltage Version)
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