TDK-Lambda PFE300SA Series Instruction Manual - Tdk-Lambda
7
TDK-Lambda
PFE300SA
・
500SA Series
INSTRUCTION MANUAL
●Selection Method of External Bulk Capacitor for Boost Voltage
Boost voltage bulk capacitor is determined by boost voltage ripple voltage, ripple current and hold-up time.
Select capacitor value such that boost voltage ripple voltage does not exceed 15Vp-p.
Note) When ambient temperature is -20℃ or less, ripple voltage of boost voltage might increase due to
ESR characteristics. Therefore, verify above characteristics by actual evaluation.
For output hold-up time, refer to separate document “PFE300SA Series Evaluation Data” or “PFE500SA
Series Evaluation Data" and use appropriate capacitor up to 1200uF maximum. It is recommended that
verification should be done through actual evaluation.
For allowable ripple current value, refer to Fig. 5-2 and select a capacitor with higher ripple current rating.
0
400
800
1200
1600
2000
0
100
200
300
400
500
Output Power (W)
R
ip
pl
e
C
ur
re
nt
(
m
A
r
m
s)
Fig. 5-2 Allowable ripple current value
The recommended boost voltage bulk capacitance value range is 390uF-1200uF.
When using with reduced the bulk capacitance value, it is necessary to reduce output power as shown in
Fig. 5-3.
Fig. 5-3 shows recommended value at 25℃ Base-plate Temperature. Temperature variance might have
some effect on the characteristics. Therefore, verify characteristics by performing actual evaluation.
Refer to “Fig. 7-1 Base-plate Measuring Point”.
Note that reducing the bulk capacitance affects output hold-up time, dynamic line response and dynamic
load response characteristics. It is recommended that verification should be done through actual
evaluation.
0
100
200
300
400
500
300
600
900
1200
Bulk Cap. (uF)
O
ut
pu
t P
ow
er
(
W
)
Fig. 5-3 Output Power v.s. Boost Voltage Bulk Capacitance
100VAC
200VAC
390
Tbp:25℃