Datasheet

rev.
page
date
DESCRIPTION: point of load converter
10 of 10
08/2007
20050 SW 112
th
Ave. Tualatin, Oregon 97062 phone [phone] fax [phone]
PART NUMBER: VPOL5A-5-SIP
7.8 VPOL5A-5-SIP Series Output Voltage Adustment.
The output Voltage of the VPOL5A-5-SIPS33A can be adjusted in the
range 0.75V to 3.63V by connecting a single resistor on the
motherboard (shown as Rtrim) in Figure 12v. When Trim resistor is not
connected the output voltage defaults to 0.75V
+Vin
Common Common
+Vo
VPOL5A-5-SIP
R trim-up
R-Load
Trim
Figure 12. 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 3.3
Vdc, Rtrim is given by:
Rtrim = 3153 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 41.71
1.50 22.98
1.80 14.96
2.00 11.75
2.50 6.93
3.30 3.15
3.63 2.20
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
18. a coaxial cable with a 50ohm termination was used to prevent
impedance mismatch reflections disturbing the noise readings at
higher frequencies5^
Figure 13. Output Voltage Ripple and Noise Measurement Set-Up
7.10 Output Capacitance
VPOL5A-5-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 induct
ance tracks.
Output capacitors with its as
sociated ESR values have an impact on
loop stability and bandwidth. converters are designed to
work with load capacitance up-to 3,000 μF. It is rec ommended that any
additional capacitance, Maximum 3,000 μF and low ESR, be
connected close to the point of load and outside the remote
compensation point.
8. Mechanical Outline Diagrams
8.1 SIP/SMT05 Mechanical Outline Diagrams
Dimensions are in millimeters and inches
Tolerance: x.xx ±0.02 in. (0.5mm) , x.xxx ±0.010 in. (0.25 mm) unless
otherwise noted
PIN CONNECTION
FUNCTION
+Output
Trim
Common
+V Input
On/Off
Pin
1
2
3
4
5
1 2
3
4
5
0.90(22.9)
0.400(10.16)
0.100(2.54)
0.700(17.78)
0.200(5.08)
0.14(3.6)
0.025(0.
64)
SIZE SIP05
0.025(0.64)
0.800(20.32)
0.22(5.6)Max.
0.19(4.7)
Figure 14 VPOL5A-5-SIP Mechanical Outline Diagram
)5110
75.0
21070
(
Vo
Rtrim
)5110
75.0
21070
(
_
Vo
Rtrim
+Vin
Common Common
+Vo
VPOL5A-5-SIP
R-Load
10uF
Tant.
1uF
Ceramic
Test Jack
=
_
_
=
_
CUI INC’s
CUI INC’s
For more information, please visit the product page.