2.6 Smoothing capacitor for boost voltage: Cbc
■
In order to smooth boost voltage, connect Cbc bBC and -BC.
Recommended capacitance of Cbc is shown in Table 2.4.
■
Install a capacitor Cbc with a rated voltage of DC420 V or higher within the allowable
capacitance.
■
When operated below 0ºC, operation may become unstable as boost ripple voltage
increases due to ESR characteristics. Choose a capacitor which has higher capacitance
than recommended.
Select a capacitor so that the ripple voltage of the boost voltage is 30 Vp-p or below.
■
If the ripple voltage of the boost voltage increases, the ripple current rating of the
smoothing capacitor may be exceeded. Check the maximum allowable ripple current of
the capacitor.
■
The ripple current changes with PCB patterns, external parts, ambient temperature, etc.
Check the actual ripple current value flowing through Cbc.
Table 2.4
Recommended
capacitance
Cbc
※
Refer to item 6 and 7 for selection method of Cbc.
2.7
Capacitor for boost voltage :C20,C30
■
Install film capacitors with a rating of 1uF/DC450V or higher as C20 and C30.
■
If C20 and C30 are not connected, the power supply or external components could be
damaged.
■
The ripple current flows into these capacitors. Check the maximum allowable ripple
current of the capacitor while selecting.
■
The frequency of the ripple current is 100 kHz to 200 kHz.
■
Ripple current values flowing into C20 and C30 as listed in Table 2.1 are shown in
Fig.2.4 and Fig.2.5.
■
The ripple current changes with PCB patterns, external parts, ambient temperature, etc.
Check the actual ripple current values flowing through C20 and C30.
Fig.2.4
Ripple current
values
C20
※
Ripple current value is total of 2 paralleled capacitors.
TUNS700F
390uF × 2 parallel
470uF ~ 2,200uF
A-5
TUNS300F
470uF
390uF ~ 2,200uF
TUNS500F
390uF × 2 parallel
390uF ~ 2,200uF
Model
Recommended capacitance
Allowable capacitance range
0
500
1000
1500
2000
2500
3000
3500
0
20
40
60
80
100
120
Ri
pp
le
cu
rre
nt
[m
Ar
ms
]
Output current [%]
TUNS300F(100VAC)
TUNS300F(200VAC)
TUNS500F(100VAC)
TUNS500F(200VAC)
TUNS700F(100VAC)
TUNS700F(200VAC)
Applications Manual
TUNS300/500/700
