LM2575

23

MOTOROLA ANALOG IC DEVICE DATA

THE LM2575–ADJ STEP–DOWN VOLTAGE REGULATOR WITH 8.0 V @ 1.0 A OUTPUT POWER

CAPABILITY. TYPICAL APPLICATION WITH THROUGH–HOLE PC BOARD LAYOUT

C1

–

100

µF, 50 V, Aluminium Electrolytic

C2

–

330

µF, 16 V, Aluminium Electrolytic

C3

–

100

µF, 16 V, Aluminium Electrolytic

D1

–

1.0 A, 40 V, Schottky Rectifier, 1N5819

L1

–

330

µH, Tech 39: 77 458 BV, Toroid Core, Through–Hole, Pin 3 = Start, Pin 7 = Finish

L2

–

25

µH, TDK: SFT52501, Toroid Core, Through–Hole

R1

–

1.8 k

R2

–

10 k

Figure 38. Schematic Diagram of the 8.0 V @ 1.0 V Step–Down Converter Using the LM2575–Adj

(An additional LC filter is included to achieve low output ripple voltage)

Figure 39. PC Board Component Side

Figure 40. PC Board Copper Side

Vref = 1.23 V

R1 is between 1.0 k and 5.0 k

D1

1N5819

L1

330

µH

Output

2

R2

10 k

R1

1.8 k

L2

25

µH

Regulated

Output Filtered

Vout2 = 8.0 V @1.0 A

Unregulated

DC Input

C2

330

µF

/16 V

C3

100

µF

/16 V

C1

100

µF

/50 V

LM2575–Adj

1

5

3ON/OFF

Gnd

+Vin

+Vin = +10 V to + 40 V

4

Feedback

Regulated

Output Unfiltered

Vout1 = 8.0 V @1.0 A

R2

R1

+Vout1

+Vin

Gndin

C1

L1

C2

D1

J1

U1 LM2575

L2

C3

+Vout2

R2 R1

Gndout

MOTOROLA

NOTE:

Not to scale.

NOTE:

Not to scale.

References