Datasheet

3A 52KHz 40V Buck DC to DC Converter

XL2576

Rev 2.6

www.xlsemi.com

8

Test Circuit and Layout guidelines

XL2576

ADJUSTABLE

CIN

C1

105

COUT

D1

L1

UNREGULATED

DC INPUT

LOAD

1

35

2

4

GND

VIN

FEEDBACK

OUTPUT

ON/OFF

ON

OFF

REGULATED OUTPUT

KEEP FEEDBACK WIRING AWAY

FROM INDUCTOR FLUX

HEAVY LINES MUST BE KEPT SHORT AND USE

GROUND PLANE CONSTRUCTION FOR BEST RESULTS

R1 1K

R2

CFF

LOCATE THE PROGRAMMING RESISTORS NEAR

THE FEEDBACK PIN USING SHORT LEADS

VOUT=1.23*(1+R2/R1)

Figure5. Standard Test Circuits and Layout Guides

Select R1 to be approximately 1K, use a 1% resistor for best stability.

C1 and CFF are optional; in order to increase stability and reduce the input power line noise, CIN

and C1 must be placed near to PIN1 and PIN3;

For output voltages greater than approximately 10V, an additional capacitor CFF is required. The

compensation capacitor is typically between 100 pf and 33 nf, and is wired in parallel with the

output voltage setting resistor, R2. It provides additional stability for high output voltage, low

input-output voltages, and/or very low ESR output capacitors, such as solid tantalum capacitors.

CFF=1/(31*1000*R2); This capacitor type can be ceramic, plastic, silver mica, etc. (Because of

the unstable characteristics of ceramic capacitors made with Z5U material, they are not

recommended.)