PDM1-S Datasheet, PDF (5/6 Pages) CUI INC – DC-DC CONVERTER

CUI Inc │ SERIES: PDM1-S │ DESCRIPTION: DC-DC CONVERTER
date 03/18/2013 │ page 5 of 6
APPLICATION NOTES
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).
Figure 1
Single Output
Vin
Cin
GND
Dual O utput
Vin
Cin
GND
DC DC
DC DC
+Vo
Cout
0V
+Vo
Cout
0V
Cout
Vo
Vin
(Vdc)
Cin
(µF)
Single Vo Cout
(Vdc)
(µF)
Dual Vo
(Vdc)
Cout
(µF)
Table 1
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
It’s not recommended to connect any external capacitors in applications with less than 0.5 watt output.
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.
Figure 2
Single Output
Vin
REG
REG
+Vo
DC DC
GND
0V
Dual Output
Vin
REG
REG
+Vo
DC DC
0V
GND
REG
-Vo
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.
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