cui.com

date

01/27/2012 │ page 4 of 5

CUI Inc

│ SERIES: VFSD1-SIP Series │ DESCRIPTION: DC-DC CONVERTER

1.

Requirement on output load

To ensure this module can operate efficiently and reliably, During operation, the minimum output load could not be less than 10% of

the full load. If the actual output power is very small, please connect a resistor with proper resistance at the output end in parallel to

increase the load, or use our company’s products with a lower rated output power (E_S-W25&F_S-W25).

2.

Overload Protection

Under normal operating conditions, the output circuit of these products has no protection against overload. The simplest method is to

connect a self-recovery fuse in series at the input end or add a circuit breaker to the circuit.

3.

Recommended testing and application circuit

If you want to further decrease the input/output ripple, an “LC” filtering network may be connected to the input and output ends

of the DC/DC converter, see (Figure 1). It should also be noted that the inductance and the frequency of the “LC” filtering network

should be staggered with the DC/DC frequency to avoid mutual interference. However, the capacitance of the output filter capacitor

must be proper. If the capacitance is too big, a startup problem might arise. For every channel of output, provided the safe and

reliable operation is ensured, the recommended capacitance of its filter capacitor sees (Table 1).

4.

Output Voltage Regulation and Over-voltage Protection Circuit

The simplest device for output voltage regulation, over-voltage and over-current protection is a linear voltage regulator with overheat

protection that is connected to the input or output end in series (Figure 2).

5.

No parallel connection or plug and play

Vin

(Vdc)

Cin

(μF)

Single Vout

(Vdc)

Cout

(μF)

Dual Vout

(Vdc)

Cout

(μF)

3.3, 5

4.7

3.3, 5

10

±5

4.7

12

2.2

9.0

4.7

±9

2.2

15

2.2

12

2.2

±12

1.0

24

1.0

15, 24

1.0

±15

0.47

External Capacitor Table (Table 1)

Figure 1

APPLICATION NOTES

Figure 2