-Vin

+Vin

RC

-Vin

+Vin

RC

-Vin

+Vin

RC

Input 5V

Input 12V

Input 24, 48V

Fig.1.4 Examples of Using an External Remote ON/OFF Circuit

Table 1.2 Specification of Remote ON/OFF

ON

OFF

¡

or below.

¡

If you do not use the Remote ON/OFF function, please short out

between the pin terminals RC and -Vin to prevent malfunction.

(2) SU/SUC10/SUT10

¡

The output of the power supply turns ON when the pin terminal

RC is connected to the pin terminal -Vin. When the pin terminal

RC is open or the voltage of the pin terminal RC is between 2.4 to

7.0 V, the output of the power supply goes OFF.

¡

When the voltage of the pin terminal RC is between 1.2 to 2.4V,

an output voltage value may be an uncertain value which is less

than the rated voltage.

¡

Please see the following diagram for how to use the pin terminal

RC.

or

Relay

or

TransistorIC

-Vin

Vcc

RC

Fig.1.5 Examples of Using an External Remote ON/OFF Circuit

Table 1.3 Specification of Remote ON/OFF

ON

OFF

¡

When the pin terminal RC is at the ”Low” level, outflowing current

is 0.5mA typ. When Vcc is used, please make sure that the volt-

age of Vcc is 7.0V or less.

¡

If you do not use the Remote ON/OFF function, please short out

between the pin terminals RC and -Vin.

2 Wiring to Input/Output

Pin Terminals

¡

Basically, SU/SUC/SUT series do not need any external capaci-

tor. However, you can create a P-shaped filter circuit by adding a

capacitor Ci near the input pin terminal and reduce reflected input

noise from a converter. Please connect the capacitor as needed.

¡

When you use a capacitor Ci, please use the one with high fre-

quency and good temperature characteristics.

¡

If the power module is to be turned ON/OFF directly with a switch,

inductance from the input line will induce a surge voltage several

times that of the input voltage and it may damage the power mod-

ule. Make sure that the surge is absorbed, for example, by con-

necting an electrolytic capacitor between the input pins.

¡

If an external filter containing L (inductance) is added to the input

line or a wire from the input source to the DC-DC converter is

long, not only the reflected input noise becomes large, but also

the output of the converter may become unstable. In such case,

connecting Ci to the input pin terminal is recommended.

¡

If you use an aluminum electrolytic capacitor, please pay attention

to its ripple current rating.

Ci

L

-Vin

+Vin

Input

Fig.2.1 Connecting an External Capacitor to the Input Side

Table 2.1 Recommended Capacitance of an External Capacitor on the Input Side [ F]

Model

Input Voltage(V)

SU/SUC1R5 SU/SUC3/SUT3 SU/SUC6/SUT6 SU/SUC10/SUT10

5

10 - 100

10 - 220

10 - 470

10 - 470

12

10 - 47

10 - 100

10 - 220

10 - 220

24

10 - 33

10 - 47

10 - 100

10 - 100

48

4.7 - 10

10 - 22

10 - 47

10 - 47

*

Please adjust the capacitance in accordance with a degree of the

effect you want to achieve.

¡

If a reverse polarity voltage is applied to the input pin terminal, the

power supply will fail.

If there is a possibility that a reverse polarity voltage is applied,

connect a protection circuit externally as described below.

(a)

Schottky barrier diode generates a power loss

of input current multiplied by forward voltage.

Input

Schottky Barrier Diode

+Vin

-Vin

DC-DC Converters PCB Mount Type

Instruction Manual

SU.SUC/SUT-53

June 26, 2020