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003-01 / 20051203 / ea335_cc.fm
• All specifications are subject to change without notice.
Characteristics, Functions, and Applications
TERMINAL CONNECTION
Be very careful with coupling input wires. An incorrect terminal
connection or polarity may damage a converter.
• OUTPUT VOLTAGE ADJUSTMENT TERMINAL (Vset)
(except CCP Type)
The following output voltages can be outputted by connecting this
terminal to an output + or – terminal. Unless the output voltage is
adjusted, this terminal should be open.
In addition, the voltages can be adjusted not by shorting these ter-
minals, but by connecting them to resistances as shown below.
• Calculation formula
Connection resistance: R(k
Ω
)
∗1
Vo=(3.3×R+36.7)/(R+10)
∗2
Vo= 2.5×[2+2.7/(R+6.8)]
∗3
Vo=2.5+9.5 (R+10.9)/(R+8.2)
∗4
Vo=2.5+22×(R+12.7)/(R+10)[Between two outputs]
∗5
Vo=(3.3×R+36.7)/(R+12.92)
∗6
Vo=2.5×[2–2.7/(R+9.5)]
If the output voltage has been adjusted to be higher, it should be
noted that the output current needs to be derated so as to be suit-
able for the maximum power. If there is a possibility that a surge
voltage is applied to the output section when this product is used at
12V or ±12V, connect a capacitor of approx. 0.01 to 0.1µF
between the Vset and output GND terminals.
To improve an accuracy of the output voltage (for example, sup-
pressed to Vo±0.5% or lower), arrange the wiring as shown below
to adjust the output voltage.
• DUAL-OUTPUT CONNECTION METHOD(except CCP Type)
As for a dual-output converter, it is also possible to obtain a dou-
ble-output voltage (24V output for ±12V output) by connecting a
load between the plus and minus outputs with the GND terminal
open.
NOISE REDUCTION
In measuring the converter noise, a value may have a significantly
large deviation according to a measuring method in case of an
inaccurate measurement. The measurement should be performed
at the base of the terminal and no loop should be made to prevent
flux from being gathered at a connection of a probe.
In addition, it should be noted that a spike voltage largely depends
upon a ripple voltmeter or a frequency band of an oscilloscope.
The TDK noise measurement is performed at the base of each ter-
minal in the 50MHz frequency band. If such significant deviation of
values is a problem, the measurement system should be reviewed.
• INPUT NOISE
This converter incorporates a filter circuit as shown below in an
input section. Therefore, it operates without any external capacitor
attached to the input section. A connection of a capacitor, how-
ever, forms
π
filter and reduces input return noise.
If there is a long distance from the input power supply to the input
section of the converter, connect a capacitor at the base of the
input terminal, if possible. The capacitor connected to the input
power supply portion does not have so much effect in some cases.
A long distance from the input power supply to the input section of
the converter may cause high impedance of an input line, thereby
increasing spike noise. Therefore, it is recommended to connect a
capacitor in this condition, if possible.
A capacity range of the external capacitor is approx. 0 to 470µF.
Select and connect the optimum one according to your conditions
for use.
• OUTPUT NOISE
If an output ripple is reduced, connect a capacitor of approx. 0 to
220µF to the output section of the converter. The noise is further
reduced by a connection of
π
filter as shown below. In this connec-
tion, the filter should be of around 0 to 100µF.
To reduce output spike noise, connect a ceramic capacitor of
approx. 0 to 1µF to the output section of the converter.
If the wiring pattern between the converter output and the load is
long, the capacitor should be located at the base of the load as far
as possible. The capacitor installed close to the base of the output
of the converter may have so much effect.
Part No. Open –Vout shorted +Vout shorted
XX03SF 3.3V 3.67V 2.84V
XX05SF5V6V4.3V
XX12SF 12V 15V —
XX12DF ±12V ±15V —
Part No. Open
–Vout connected
with resistance
+Vout connected
with resistance
XX03SF 3.3V 3.3 to 3.67V
∗
1
3.3 to 2.84V
∗
5
XX05SF 5V 5 to 6
∗
2
5 to 4.3V
∗
6
XX12SF 12V 12 to 15V
∗
3
—
XX12DF ±12V ±12 to ±15V
∗
4
—
Variable
resistance
+Vout
+Vset
–Vout
+Vin
–
Vin
+
+
–
Power
supply
Load
DC-DC converter
+Vout
–
Vout
+
DC-DC converter
++
Load
DC-DC converter
+Vout
–Vout
+Vout
–Vout
DC-DC converter
Load
+
