Datasheet

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th
Ave. Tualatin, Oregon 97062 phone [phone] fax [phone]
7.8 VPOL16A-12-SIP Series Output Voltage
Adustment.
The output Voltage of the VPOL16A-12-SIP can be adjusted in the
range 0.75V to 5.0V by connecting a single resistor on the motherboard
(shown as Rtrim) in Figure 13. When Trim resistor is not connected the
output voltage defaults to 0.75V
+Vin
Common Common
+Vo
VPOL16A-12-SIP
R trim-up
R-Load
Trim
Figure 13. Trim-up Voltage Setup
The value of Rtrim-up defined as:
Where: Rtrim-up is the external resistor in ohm,
Vo is the desired output voltage
To give an exa mple of the above calculation, to set a voltage of 3.3Vdc,
Rtrim is given by:
Rtrim = 3117 ohm
For various output values various resistors are calculated and provided
in Table 3 for co nvenience.
Vo,set (V) Rtrim (Kohm)
0.75 Open
1.20 22.33
1.50 13.0
1.80 9.0
2.00 7.4
2.50 5.0
3.30 3.12
5.0 1.47
Table 3 – Trim Resistor Values
7.9 Output Ripple and Noise Measurement
The test set-up for noise and ripple measurements is shown in Figure
14. a coaxial cable with a 50ohm termination was used to prevent
impedance mismatch reflections disturbing the noise readings at higher
frequencies.
Figure 14. Output Voltage Ripple and Noise Measurement Set-Up
7.10 Output Capacitance
CUI INC's VPOL16A-12-SIP series converters provide unconditional
stability with or without external capacitors. For good transient response
low ESR output capacitors should be located close to the point of load.
For high current applications point has already been made in layout
considerations for low resistance and low inductance tracks.
Output capacitors wi
th its associated ESR values have an impact on
loop stability and bandwidth. CUI INC's converters are designed to
work with load capacitance up-to 8,000uF. It is reco mmended that any
additional capacitance, Maximum 8,000uF and low ESR, be connected
close to the point of load and outside the remote compensation point.
7.11 VPOL16A-12-SIP Reflow Profile
An example of the VPOL16A-12-SIP reflow profile is given in Figure 15.
Equipment used: SMD HOT AIR REFLOW HD-350SAR
Alloy: AMQ-M293TA or NC-SMQ92 IND-82088 SN63
REFLOW PROFILE
0
40
80
120
160
200
240
0 30 60 90 120 150 180 210 240
TIME (SECONDS)
TEMPERATURE (C)
Figure 15 VPOL16A-12-SIP Reflow Profile
)1000
75.0
10500
(
Vo
Rtrim =
)1000
75.03.3
10500
(Rtrim =
+Vin
Common Common
+Vo
VPOL16A-12-SIP
R-Load
10uF
Tant.
1uF
Ceramic
Test Jack
_
_
_
_
rev.
rev.
page
date
DESCRIPTION: point of load converter
11 of 12
08/2007
PART NUMBER: VPOL16A-12-SIP
For more information, please visit the product page.