PRMC1-S Datasheet, PDF (5/6 Pages) CUI INC – DC-DC CONVERTER

CUI Inc │ SERIES: PRMC1-S │ DESCRIPTION: DC-DC CONVERTER
date 03/20/2013 │ 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 5% 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. Recommended circuit
This series has been tested according to the following recommended testing circuit before leaving the factory. This series should be
tested under load (see Figure 2). If you want to further decrease the input/output ripple, you can increase the capacitance accordingly
or choose capacitors with low ESR. 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 capaci-
tance must be less than the maximum capacitive load (see Table 1).
9LQ
/LQ _

9R
&LQ
*1'
9F ^&G

' ,F _{5 }

&V
&RXW
9

Figure 2
Table 1
Vin
(Vdc)
5
12
24
48
Cin
(µF)
100
100
10
10
Lin
(µH)
4.7-120
4.7-120
4.7-120
4.7-120
Cs
(µF)
10-22
10-22
10-22
10-22
Cout
(µF)
47
47
47
47
                                                                                                          
3. CTRL Terminal
When open or applied high impedance, the converter will turn on. When it’s pulled high, the converter will shutdown. The input cur-
rent should between 5-10mA. Exceeding the maximum 20mA will cause permanent damage to the converter. The value for R can be
derived as follows:
4. Input Current
R =V^{C −VD −1.0} −300
I_C
When it is used in an unregulated condition, make sure that the input fluctuations and ripple voltage do not exceed the module stan-
dard. Refer to Figure 3 for the startup current of this dc-dc module.
Figure 3
Ip
Input Voltage
Range
Input Voltage (V)
Vin
(Vdc)
5
12
24
48
Ip
(mA)
470
180
110
42
Note:
1. Minimum load shouldn't be less than 5%, otherwise ripple may increase dramatically. Operation under minimum load will not damage the converter, however, they may
not meet all specifications listed.
2. Maximum capacitive load is tested at input voltage range and full load.
3. All specifications are measured at Ta=25°C, humidity<75%, nominal input voltage and rated output load unless otherwise specified.
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