Advance Data Sheet: Maxeta
TM
iFA Series
©2005 TDK Innoveta Inc.
iFA Advance Datasheet 6/6/2005
℡
(877) 498-0099
14/18
If the output voltage adjustment feature is
not used, the Vout(+) pin should be shorted
to the sense(+) pin and the Vout(-) pin
should be shorted to the sense(-) pin by
jumper wires.
Figure Trim Down Connection
S(+)
Vo(+)
S(-)
Vo(-)
Trim
Load
Rext2
Co
To trim the output voltage down, a fixed or
variable resistor, Rext2, shall be connected
between the trim pin and the sense(-) pin
while the Vout(-) pin and the sense(-) pin are
shorted by a jumper wire. Vout(+) pin and
the sense(+) pin should also be shorted by a
jumper wire as shown below. The resistor,
Rext2, can be chosen according to the
following equation:
Rext2
Vo_down
0.331
+
4.787591
0.171506Vo_down
−
Trim-dow n Resistance vs. Vout
1
10
100
1000
10000
16
18
20
22
24
26
28
Output Voltage (V)
T
ri
m
R
e
s
is
ta
n
c
e
(
K
Ω
)
In order to trim the output voltage from the
minimum value (-40% down) to the
maximum value (+10% up) in a linear
fashion, a fixed resistor, Rext, should be
connected between the trim pin and the
sense(-) pin while a 50K
Ω
variable resistor,
Rv, shall be connected between the Vout(+)
pin and the sense(+) pin as shown below.
When Rext=5.11K
Ω
, the voltage trim rate is
changed to approximately 0.459V / K
Ω
starting from 16.8V. The resistor, Rv, should
be chosen according to the following
equation:
Rv
≅
2.17833
×
(Vo_d – 12.862) (K
Ω
)
where Vo_d is the desired output voltage.
Figure Lin ea r Trim C onn ection
S(+ )
V o(+ )
S(-)
V o(-)
Trim
Load
R ext
C o
R v
Linear Trim Resistance vs. Vout
8.0
12.0
16.0
20.0
24.0
28.0
32.0
36.0
40.0
16
19
22
25
28
31
Output Voltage (V)
T
ri
m
R
e
s
is
ta
n
c
e
(
K
)
