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-down Resistance vs. Vout
1
10
100
1000
10000
16 18 20 22 24 26 28
Output Voltage (V)
Trim R esista nce (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 50KΩ variable resistor,
Rv, shall be connected between the Vout(+)
pin and the sense(+) pin as shown below.
When Rext=5.11KΩ, the voltage trim rate is
changed to approximately 0.459V / KΩ
starting from 16.8V. The resistor, Rv, should
be chosen according to the following
equation:
Rv ≅ 2.17833 × (Vo_d – 12.862) (KΩ)
where Vo_d is the desired output voltage.
Figu re Lin ear Trim C onn ectio n
S(+ )
Vo( +)
S(-)
Vo( -)
Trim
Loa d
Rex t
Co
Rv
Linear Trim Res istance 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)
Trim Resistance (K )