cui.com

CUI Inc

│ SERIES: VWQBS2-SIP │ DESCRIPTION: DC-DC CONVERTER

date

09/10/2012 │ page 4 of 5

1.

Requirement on Output Load

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

load, and that this product should never be operated under no 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.

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 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).

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 greatest capacitance of its filter capacitor see

(Table 1).

4.

CTRL Terminal

When open or high impedance, the converter work well; When this pin is ‘high’; the converter shutdown; It should be note that the

input current should between 5~10 mA,exceeding the maximum 20 mA will cause permanence damage to the converter. The value of

Vc not limited and desirable 5 Vdc, 12 Vdc, or directly with Vin. The value of R can be derived as follows:

5.

Input Current

Nominal input voltage range. The input current of the power supply must be sufficient to the startup current (Ip) of the DC-DC

module.

General: Ip ≤1.4*Iin-max

6.

No parallel connection or plug and play

+Vo

0V

Cout

C1

Vin

GND

2

1

6

9

3

Lin

Vc

R

Ic

C2

D1

Table 1

APPLICATION NOTES

Input Voltage (V)

Inp ut Voltage

Ra nge

Ip

R=

V

I

C

Figure 1

C1/C2

10 ~ 100 μF

Lin

4.7 ~ 120 μH

Cout

100 μF

Vin

(Vdc)

Fuse (slow-blow type)

(mA)

24

250

48

150