LM2599T-3.3 National Semiconductor, LM2599T-3.3 Datasheet - Page 28

• Manufacturer Part Number: LM2599T-3.3
• Description: Voltage Regulator IC
• Manufacturer: National Semiconductor

Specifications of LM2599T-3.3

• Output Voltage: 3.3VDC
• Output Current: 3A
• No. Of Pins: 7
• Peak Reflow Compatible (260 C): No
• Leaded Process Compatible: No
• Mounting Type: Through Hole
• Package / Case: 7 Lead
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Application Information
quirement however, that there be a minimum load of 1.2A on
the regulated positive output for the charge pump to work
correctly. Also, resistor R1 is required to limit the charging
current of C1 to some value less than the LM2599 current
limit (typically 4.5A).
This method of generating a negative output voltage without
an additional inductor can be used with other members of
the Simple Switcher Family, using either the buck or boost
topology.
TYPICAL THROUGH HOLE PC BOARD LAYOUT, FIXED OUTPUT (1X SIZE), DOUBLE SIDED
C
C
D1:
L1:
R
C
C
Thermalloy Heat Sink # 7020
IN
OUT
PULL UP
DELAY
SD/SS
:
:
— 47 µH, L39, Renco, Through Hole
— 5A, 40V Schottky Rectifier, 1N5825
:
:
— 470 µF, 50V, Aluminum Electrolytic Panasonic, “HFQ Series”
— 330 µF, 35V, Aluminum Electrolytic Panasonic, “HFQ Series”
:
— 0.1 µF
— 0.1 µF
— 10k
(Continued)
28
FIGURE 31. Charge Pump for Generating a
Low Current, Negative Output Voltage
DS012582-51
DS012582-48