Datasheet

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CUI Inc │ SERIES: PQMC3-S │ DESCRIPTION: DC-DC CONVERTER date 07/07/2014 │ page 5 of 6
1. Output load requirement
Toensurethismodulecanoperateefciently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3andTable3).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lter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 4).
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
current 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
Whenitisusedinanunregulatedcondition,makesurethattheinputuctuationsandripplevoltagedonotexceedthemodule
standard.RefertoFigure5andTable5forthestartupcurrentofthisdc-dcmodule.
Single
Vout
(Vdc)
Max. Capacitive
Load
(μF)
Dual
Vout
(Vdc)
Max. Capacitive
Load
1
(μF)
3.3 2700 -- --
5 2200 5 1000
9 1000 9 680
12 680 12 470
15 470 15 330
24 330 -- --
Table 4
Note: 1.Foreachoutput.
APPLICATION NOTES
Figure 3
Figure 5
Table 3
Vin
(Vdc)
Cin1
(µF)
Cin2
(µF)
Lin
(µH)
Cs
1
(µF)
Cout
(µF)
Lout
2
(µH)
Cd
(nF/V)
5 100 47 4.7~12 10~22 100 2.2~10 47/100
12 100 47 4.7~12 10~22 100 2.2~10 47/100
24 10 1 4.7~12 10~22 100 2.2~10 47/100
48 10 1 4.7~12 10~22 100 2.2~10 47/100
Single output Dual output
9R
9
&RXW



&V
&LQ
9LQ
*1'



9F
5
/LQ
,F
'
&G
&LQ
9R
9
&RXW



&RXW
/RXW
/RXW
9R
&LQ
9LQ
*1'


/LQ

9F
5
,F
'
&G
&LQ
Note: 1.Forsingleoutputonly
 2.Fordualoutputonly
300
0.1
−
−−
=
C
DC
I
VV
R
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specicationslisted.
2. Maximum capacitive load is tested at input voltage range and full load.
 3.AllspecicationsaremeasuredatTa=25°C,humidity<75%,nominalinputvoltageandratedoutputloadunlessotherwisespecied.
Range
InputVoltage
Input Curre nt(A)
InputVoltage (V)
Ip
Vin
(Vdc)
Ip
(mA)
5 1110
12 640
24 325
48 160
Table 5
V
c
: Control pin input voltage
V
D
:ForwardvoltagedropofdiodeD1
I
C
: Input current to control pin
R: Resistor of control circuit
Vin
GND
+Vo
-Vo
(0V)
EUT
LOAD
Ctrl
Cd
D1
R
Vc
Figure 4
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