AA
AAEE
EEVV
VV
22
2244
44VV
VV&&
&&44
4488
88VV
VV
II
IInn
nnpp
ppuu
uutt
tt
SS
SSee
eerr
rrii
iiee
eess
ss
DD
DDCC
CC-
-DD
DDCC
CC
CC
CCoo
oonn
nnvv
vvee
eerr
rrtt
ttee
eerr
rrss
ss
SS
SSii
iinn
nngg
ggll
llee
ee
AA
AAnn
nndd
dd
DD
DDuu
uuaa
aall
ll
OO
OOuu
uutt
ttpp
ppuu
uutt
tt,,
,,
22
2255
55WW
WW
DD
DDCC
CC-
-DD
DDCC
CC
CC
CCoo
oonn
nnvv
vvee
eerr
rrtt
ttee
eerr
rrss
ss
Page 2
USA Europe Asia
TEL: 1-760-930-4600 44-(0)1384-842-211 852-2437-9662
FAX: 1-760-930-0698 44-(0)1384-843-355 852-2402-4426 www.astec.com
Input Reverse Voltage Protection
Under installation and cabling conditions where
reverse polarity across the input may occur, reverse
polarity protection is recommended. Protection can
easily be provided as shown in Figure 3. In both cases
the diode used is rated for 4A/100V. Placing the diode
across the inputs rather than in-line with the input
offers an advantage in that the diode only conducts in
a reverse polarity condition, which increases circuit efficiency and thermal performance.
Input Undervoltage Protection
The AEV is protected against undervoltage on the input. If the input voltage should drop below the
acceptable range, the converter will shut down. It will automatically restart when the undervoltage
condition is removed.
Input Overvoltage Protection
The AEV is protected against overvoltage on the input. If the input voltage should rise above the
acceptable range, the converter will shut down. It will automatically restart when the undervoltage
condition is removed.
Input Filter
Input filters are included in the converters to
help achieve standard system emissions certi-
fications. Some users however, may find that
additional input filtering is necessary. The AEV
series has an internal switching frequency of
330 kHz so a high frequency capacitor mount-
ed close to the input terminals produces the
best results. To reduce reflected noise, a capacitor can be added across the input as shown in
Figure 4, forming a πfilter. A 47µF/100V electrolytic capacitor is recommended for C1.
For conditions where EMI is a concern, a dif-
ferent input filter can be used. Figure 5 shows
an input filter designed to reduce EMI effects.
L1 is a 1mH common mode inductor, C1is a
47µF/100V electrolytic capacitor, and C2is a
1µF/100V metal film or ceramic high frequency
capacitor, and Cy1 and Cy2 are each 4700 pF
high frequency ceramic capacitors.