ncp1522b ON Semiconductor, ncp1522b Datasheet - Page 12

• Manufacturer Part Number: ncp1522b
• Description: 3 Mhz, 600 Ma Step-down Dc-dc Converter
• Manufacturer: ON Semiconductor

Output Capacitor Selection
desired output ripple voltage. Ceramic capacitors with low
ESR values will have the lowest output ripple voltage and
are strongly recommended. The output capacitor requires
an X7R dielectric.
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•
•
•
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Selecting the proper output capacitor is based on the
The output ripple voltage in PWM mode is given by:
DV OUT + DI L
DV
DI
f
C
ESR: Output Capacitor Serial Resistor
SW
OUT
L:
OUT
: Switching Frequency
Peak to Peak Inductor Ripple Current
: Output Capacitor
: Output Voltage Ripple in PWM Mode
4
f SW
1
C OUT
) ESR
http://onsemi.com
(eq. 6)
NCP1522B
12
Feed-Forward Capacitor Selection
response and is critical to obtain good loop stability.
or higher ceramic capacitor is needed. Choose a small
ceramic capacitor X7R dielectric.
Table 4. LIST OF OUTPUT CAPACITORS
The feed-forward capacitor sets the feedback loop
Given that the compensation is internally fixed, an 18 pF
Taiyo Yuden
Murata
TDK
GRM188R60J475KE
GRM21BR71C475KA
GRM188R60OJ106ME
GRM21BR60J106ME19L
JMK212BY475MG
JMK212BJ106MG
C2012X5ROJ475KB
C1632X5ROJR75KT
C2012X5ROJ106K
4.7 mF
4.7 mF
4.7 mF
10 mF
10 mF
10 mF