4

shown in the Figure 1 test circuit, system performance will be as shown in system parameters section

of Electrical Characteristics.

Note 6: The switching frequency is reduced when the second stage current limit is activated. The amount

of reduction is determined by the severity of current over-load.

Note 7: No diode, inductor or capacitor connected to output pin.

Note 8: Feedback pin removed from output and connected to 0V to force the output transistor switch ON.

Note 9: Feedback pin removed from output and connected to 12V for the 3.3V, 5V, and the ADJ. version,

and 15V for the 12V version, to force the output transistor switch OFF.

Note 11: Junction to ambient thermal resistance (no external heat sink) for the TO-220 package mounted

Note 12: Junction to ambient thermal resistance with the TO-263 package tab soldered to a single

Note 13: Junction to ambient thermal resistance with the TO-263 package tab soldered to a single sided

Note 14: Junction to ambient thermal resistance with the TO-263 package tab soldered to a double sided

Normalized Output Voltage

Line Regulation

Efficiency

Switch Saturation

Voltage

Switch Current Limit

Dropout Voltage

1.5

1.0

0.5

0

-0.5

-1.0

-50 -25

0 25 50 75

0

5 10 15 20 25 30 35 40

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

INPUT VOLTAGE (V)

0

5 10 15 20 25 30 35 40

65

70

75

80

85

90

95

INPUT VOLTAGE (V)

3.3V

5V

12V

20V

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

0

12

3

4

SWITCH CURRENT (A)

V=12V

IN

T=-40 C

J

0

25 C

0

125 C

0

-50 -25

0 25 50 75

5.5

5.0

4.5

4.0

3.5

V=12V

V=5V

IN

OUT

-50 -25

0 25 50 75

1.6

1.4

1.2

1.0

0.8

0.6

I=3A

LOAD

I=1A

LOAD

LM2596 Simple switcher Power Converter 150kHz

3A Step-Down Voltage Regulator