3.0A, 150kHz, Step-Down Switching Regulator

LM2596

(Unless otherwise specified, Vin = 12V for the 3.3V, 5.0V, and Adjustable version, Vin = 25V for the 12V versio

ILoad = 500 mA. For typical values Tj = 25°C, for min/max values TJ is the operating junction temperature ran

that applies [Note 2], unless otherwise noted.)

All Output Voltage Versions

1. External components such as the catch diode, inductor, input and output capacitors can affect

switching regulator system performance. When the LM2596 is used as shown in the Figure 1 test

circuit, system performance will be as shown in system parameters section .

3. The oscillator frequency reduces to approximately 18kHz in the event of an output short or an

overload which causes the regulated output voltage to drop approximately 40% from the nominal

output voltage. This self protection feature lowers the average dissipation of the IC by lowering the

minimum duty cycle from 5% down to approximately 2%.

4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to output pin.

5. Feedback (Pin 4) removed from output and connected to 0 V.

6. Feedback (Pin 4) removed from output and connected to +12V for the Adjustable, 3.3V, and 5.0V

versions, and '+25 V for the 12V versions, to force the output transistor “off”.C195

7. Vin = 40 V.

11.4

-

12.6

11.52

12

12.48

Max

Unit

Feedback Bias Current (Vout=5.0V [Adjustable Version Only])

Characteristics

Symbol

Min

TYP

HTC

−

4 −

127

150

173

Oscillator Frequency [Note 3]

Fosc

173

Saturation Voltage (Iout=3.0A [note 4])

Vsat

110

-

1.4

-

-

1.5

-

1.16

3.6

4.5

6.9

Current Limit (Peak Current [Note 3 and 4])

3.4

-

7.5

Quiescent Current [Note 6]

Output = 0V

--

-5

--

Standby Quiescent Current (ON/OFF Pin = 5.0V ("off"))

-80

--

Vout=0V

ON/OFF Pin Logic Input Level (Test circuit Figure 2)

0.6

Vout=Nominal Ouput Voltage

2.0

-

-

1.3

-

-

0.6

nA

kHz

V

%

A

mA

mA

㎂

-

-

Max Duty Cycle ("0") [Note 5]

DC

-

100

Output = -1.0V

-2

50

30

250

200

-

10

-

2.0

1.3

V

ON/OFF Pin Input Current (Test Circuit Figure 2)

㎂

-5

15

-

0.02

5.0