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APPLICATION INFORMATION

Layout Guidelines

LM2575-xx

Fixed Output

100

µF

+

1

3

GND

5

D1

2

L1

330

µH

330

µF

+

4

L

O

A

D

Unregulated

DC Input

D1 = Schottky

L1 = 330

µH

Fixed Output Voltage Versions

LM2575

(ADJ)

100

µF

+

1

3

GND

5

ON/OFF

D1

11DQ06

OUTPUT

2

L1

330

µH

330

µF

+

FEEDBACK

4

L

O

A

D

7-V to 60-V

Unregulated

DC Input

Adjustable Output Voltage Versions

Where,

R1 = 2 kW

R2 = 6.12 kW

R2

R1

ON/OFF

OUTPUT

FEEDBACK

LM2575

1-A SIMPLE STEP-DOWN SWITCHING VOLTAGE REGULATOR

SLVS569D – JANUARY 2005 – REVISED JULY 2005

With any switching regulator, circuit layout plays an important role in circuit performance. Wiring and parasitic

inductances, as well as stray capacitances, are subjected to rapidly switching currents, which can result in

unwanted voltage transients. To minimize inductance and ground loops, the length of the leads indicated by

heavy lines should be minimized. Optimal results can be achieved by single-point grounding (see Figure 2) or by

ground-plane construction. For the same reasons, the two programming resistors used in the adjustable version

should be located as close as possible to the regulator to keep the sensitive feedback wiring short.

A.

Pin numbers are for the KTT (TO-263) package.

Figure 2. Test Circuit and Layout Guidelines

7