TDK Belleta iEA Series - Manual (Page 38)

Data Sheet: Belleta ® iEA Series –Single Output Eighth Brick
©2004 TDK Innoveta® Inc.
iEAFullDatasheet 032707 3/29/2007 Revision 2.0 ℡ (877) 498-0099
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Vin(-)
On/ Off
Vin (+)
On/Off Circuit for positive or negative
logic
Output Voltage Adjustment: The output
voltage of the power module may be
adjusted by using an external resistor
connected between the Vout trim terminal
(pin 6) and either the Sense (+) or Sense (-)
terminal. If the output voltage adjustment
feature is not used, pin 6 should be left
open. Care should be taken to avoid
injecting noise into the power module’s trim
pin. A small 0.01uF capacitor between the
power module’s trim pin and Sense (-) pin
may help avoid this.
Sense(+)
Vout(+)
Vout(-)
Rdown
Trim
Sense(-)
Circuit to decrease output voltage
With a resistor between the trim and Sense
(-) terminals, the output voltage is adjusted
down. To adjust the output voltage down a
percentage of Vout (%Vo) from Vo,nom, the
trim resistor should be chosen according to
the following equation:
For all outputs except 1.2V:
Rdown
510
%Vo
10.2
−




1000
⋅ :=
For 1.2V output only:
Rdown
100
%Vo
2
−




1000
⋅ :=
The current limit set point does not increase
as the module is trimmed down, so the
available output power is reduced.
Sense(+)
Trim
Vout(-)
Sense(-)
Vout(+)
Rup
Circuit to increase output voltage
With a resistor between the trim and sense
(+) terminals, the output voltage is adjusted
up. To adjust the output voltage up a
percentage of Vout (%Vo) from Vo,nom the
trim resistor should be chosen according to
the following equation:
For all outputs except 1.2V:
Rup
5.1Vonom 100 %Vo + ( ) ⋅
Vref %Vo ⋅
510
%Vo
− 10.2 −




1000 ⋅ :=
For 1.2V output only:
Rup
100
%Vo




1000
⋅ :=
The value of Vref is found in the Electrical
Data section for the power module of
interest. The maximum power available
from the power module is fixed. As the
output voltage is trimmed up, the maximum
output current must be decreased to
maintain the maximum rated power of the
module. As the output voltage is trimmed,
the output over-voltage set point is not
adjusted. Trimming the output voltage too
high may cause the output over voltage
protection circuit to be triggered.