lm2773tlx National Semiconductor Corporation, lm2773tlx Datasheet - Page 10

• Manufacturer Part Number: lm2773tlx
• Description: Low-ripple 1.8v/1.6v Spread-spectrum Switched Capacitor Step-down Regulator
• Manufacturer: National Semiconductor Corporation

www.national.com
TABLE 1. LM2773 Performance with Different Capacitor
CAPACITOR
CONFIGURATION
(V
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
IN
OUT
1
IN
OUT
1
IN
OUT
1
IN
OUT
1
IN
OUT
1
IN
, C
, C
, C
, C
, C
= 1µF,
= 1µF,
= 0.47µF,
= 0.47µF,
= 0.47µF,
= 3.6V)
2
2
2
2
2
= 4.7µF,
= 2.2µF,
= 4.7µF,
= 3.3µF,
= 3.3µF,
= 1µF
= 1µF
= 1µF
= 1µF
= 0.47µF
Configurations, 1.8V Mode (Note 14)
TYPICAL
OUTPUT
RIPPLE
10mV
16mV
12mV
12mV
13mV
10
Note 14: Refer to the text in the Recommended Capacitor Configurations
section for detailed information on the data in this table
Layout Guidelines
Proper board layout will help to ensure optimal performance
of the LM2773 circuit. The following guidelines are recom-
mended:
•
•
•
Place capacitors as close to the LM2773 as possible, and
preferably on the same side of the board as the IC.
Use short, wide traces to connect the external capacitors
to the LM2773 to minimize trace resistance and
inductance.
Use a low resistance connection between ground and the
GND pin of the LM2773. Using wide traces and/or multiple
vias to connect GND to a ground plane on the board is
most advantageous.