LM2574, NCV2574

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2

Figure 1. Block Diagram and Typical Application

7.0 - 40 V

Unregulated

DC Input

L1

330

mH

Pwr

Gnd

5

22

mF

4ON/OFF

3

Output

7

Feedback

1

D1

1N5819

220

mF

Typical Application (Fixed Output Voltage Versions)

Representative Block Diagram and Typical Application

Unregulated

DC Input

5

Feedback

1

L1

D1

R2

R1

1.0 k

Output

7

Pwr Gnd

4

ON/OFF

3

Reset

Latch

Thermal

Shutdown

52 kHz

Oscillator

1.235 V

Band-Gap

Reference

Freq

Shift

18 kHz

Comparator

Fixed Gain

Error Amplifier

Current

Limit

Driver

1.0 Amp

Switch

ON/OFF

3.1 V Internal

Regulator

Load

Output

Voltage Versions

3.3 V

5.0 V

12 V

15 V

R2

(

W)

1.7 k

3.1 k

8.84 k

11.3 k

For adjustable version

R1 = open, R2 = 0

W

LM2574

5.0 V Regulated

Output 0.5 A Load

Sig

Gnd

2

Sig Gnd

2

(12)

(14)

(3)

(4)

(6)

(5)

(5)

(12)

(3)

(4)

(14)

(6)

NOTE: Pin numbers in ( ) are for the SO−16W package.

Rating

Symbol

Value

Unit

Maximum Supply Voltage

45

V

ON/OFF Pin Input Voltage

−

−0.3 V

V

Output Voltage to Ground (Steady State)

−

−1.0

V

DW Suffix, Plastic Package Case 751G

Max Power Dissipation

Internally Limited

W

Thermal Resistance, Junction−to−Air

145

°C/W

N Suffix, Plastic Package Case 626

Max Power Dissipation

Internally Limited

W

Thermal Resistance, Junction−to−Ambient

100

°C/W

Thermal Resistance, Junction−to−Case

5.0

°C/W

Storage Temperature Range

−65

°C to +150°C

°C

Minimum ESD Rating

−

2.0

kV

(Human Body Model: C = 100 pF, R = 1.5 k

W)

Lead Temperature (Soldering, 10 seconds)

−

260

°C

Maximum Junction Temperature

150

°C

Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality

should not be assumed, damage may occur and reliability may be affected.

NOTE: ESD data available upon request.