LSP5502

2A Synchronous Step Down DC/DC Converter

7/11

Rev. 1.7

www.liteon-semi.com

And the proper value for CCOMP2 is:

COMP

ESRCOUT

OUT

2

COMP

R

R

C

C

=

(13)

Though CCOMP2 is unnecessary when the output capacitor has sufficiently low ESR, a small value CCOMP2 such as

100pF may improve stability against PCB layout parasitic effects.

Table 3 shows some calculated results based on the compensation method above.

VOUT

COUT

RCOMP

CCOMP

CCOMP2

1.0V

22µF Ceramic

1.5kΩ

10nF

100pF

1.2V

22µF Ceramic

1.7kΩ

10nF

100pF

1.8V

22µF Ceramic

2.2kΩ

6.8nF

100pF

2.5V

22µF Ceramic

3.6kΩ

4.7nF

100pF

3.3V

22µF Ceramic

4.7kΩ

3.3nF

47pF

5V

22µF Ceramic

6.8kΩ

2.2nF

47pF

1.0V

47µF SP Cap

3.0kΩ

6.8nF

470pF

1.2V

47µF SP Cap

3.6kΩ

4.7nF

330pF

1.8V

47µF SP Cap

5.6kΩ

3.3nF

220pF

2.5V

47µF SP Cap

6.8kΩ

2.2nF

200pF

3.3V

47µF SP Cap

10kΩ

2.0nF

150pF

5V

47µF SP Cap

10kΩ

2.2nF

150pF

1.0V

470µF/6.3V/30mΩ

10kΩ

2.2nF

1nF

1.2V

470µF/6.3V/30mΩ

10kΩ

3.3nF

1nF

1.8V

470µF/6.3V/30mΩ

10kΩ

4.7nF

1nF

2.5V

470µF/6.3V/30mΩ

10kΩ

6.8nF

1nF

3.3V

470µF/6.3V/30mΩ

10kΩ

8.2nF

1nF

5V

470µF/10V/30mΩ

10kΩ

10nF

1nF

Table3. Typical Compensation for Different Output Voltages and Output Capacitors

Free Datasheet http://www.nDatasheet.com