cui.com

CUI Inc

│ SERIES: PDM1-S │ DESCRIPTION: DC-DC CONVERTER

date 03/18/2013

│ page 5 of 6

1. Output load requirement

To ensure this module can operate efficiently and reliably, the minimum output load may not be less than 10% of the full load during

operation. If the actual output power is low, connect a resistor at the output end in parallel to increase the load.

2. Overload Protection

Under normal operating conditions, the output circuit of this product has no protection against overload. The simplest method to add

this is to add a circuit breaker to the circuit.

3. Recommended circuit

If you want to further decrease the input/output ripple, you can increase the capacitance accordingly or choose capacitors with low

ESR(see Figure 1). However, the capacitance of the output filter capacitor must be appropriate. If the capacitance is too high, a

startup problem might arise. For every channel of the output, to ensure safe and reliable operation, the maximum capacitance must

be less than the maximum capacitive load (see Table 1).

4. Output Voltage Regulation and Over-voltage Protection Circuit

The device for output voltage regulation, over-voltage and over-current protection is a linear regulator and a capacitor filtering net-

work with overheat protection, which can be connected to the input or output end in series (see Figure 2). The recommended capaci-

tance of its filter capacitor (see Table 1), and the linear regulator is based on the actual voltage and current required.

APPLICATION NOTES

Figure 1

Figure 2

Vin

GND

+Vo

0V

DC

Cin

DC

Cout

Cout

Vo

Dual Output

Single Output

Vin

GND

+Vo

0V

DC

Cin

DC

Cout

Table 1

Vin

(Vdc)

Cin

(µF)

Single Vo

(Vdc)

Cout

(µF)

Dual Vo

(Vdc)

Cout

(µF)

5

4.7

5

10

±5

4.7

12

2.2

12

2.2

±12

1

15

2.2

15

1

±15

0.47

24

1

24

1

±24

0.47

Vin

GND

0V

+Vo

DC DC

-Vo

REG

REG

REG

Vin

GND

0V

+Vo

DC DC

REG

REG

Dual Output

Single Output

It’s not recommended to connect any external capacitors in applications with less than 0.5 watt output.

Note:

1. Operation under minimum load will not damage the converter; however, they may not meet all specifications listed.

2. Max. capacitive load tested at input voltage range and full load.

3. All specifications measured at: Ta=25°C, humidity<75%, nominal input voltage and rated output load, unless otherwise specified.