Datasheet

rev.
page
date
DESCRIPTION: point of load converter
6 of 10
08/2007
20050 SW 112
th
Ave. Tualatin, Oregon 97062 phone [phone] fax [phone]
PART NUMBER: VPOL5A-5-SIP
6. Safety
6.1 Input Fusing and Safety Considerations.
Agency Approvals: The power supply shall be submitted to and
receive formal approval from the following test agencies.
1.The power supply shall be approved by a nationally recognized
testing laboratory to UL/CSA 60950 3
rd
Edition (North America) and
EN60950 (International)
2. CB Certificate from an internationally recognized test house in
accordance with EN 60950.
The VPOL5A-5-SIP series converters do not have an internal fuse.
However, to achieve maximum safety and system protection, always
use an input line fuse. The safety agencies require a time-delay fuse
with a maximum rating of 10 A.
7. Applications
7.1 Layout Design Challenges.
In optimizing thermal design the PCB is utilized as a heat sink. Also
some heat is transferred from the SIP module to the main board
through connecting pins. The system designer or the end user must
ensure that othe
r components and metal in the vicinity of the
VPOL5A-5-SIP series meet the spacing requirements to which the
system is approved.
Low resistance and low inductance PCB layout traces are the norm
and should be used where possible. Due consideration must also be
given to proper low impedance tracks between power module, input
and output grounds. The recommended SIP footprint as shown in
figure 5.
All Dimmension In Inches(mm)
Tolerance :
.XX= .02 (
0.
5 )
.XXX= .010 (
0.25
)
LAYOUT PATTERN
T
OP VIEW
0.24(6.1)
0
.20(5.1)
1.1mm PLATED THROUGH HOLE
1.6mm PAD SIZE
Figure 5. Recommended SIP Footprint
7.2 Convection Requirements for Cooling
To predict the ap proximate cooling needed for the module, refer to the
Power De-rating curves in Figures 10 to 13. These derating curves are
approximations of the ambient temperatures and airflows required to
keep the power module temperature below its maximum rating. Once
the module is assembled in the actual system, the module’s
temperature should be checked as shown in Figure 6 to ensure it does
not exceed 110°C.
Proper cooling can be verified by measuring the power module’s
temperature at Q1-pin 6 as shown in Figure 6.
25.4(1.0)
12.7(0.5)
76.2(3.0)
Power Module
A
ir
flow
Thermocuple Location
for measuring
ambient temperature
and airflow
Bakelite
Wind
Tunnel
Note : Dimensions are in millimeters and (inches)
Figure 6. Thermal Test Setup
7.3 Thermal Considerations
The power module operates in a variety of thermal environments;
however, sufficient cooling should be provided to help ensure reliable
operation of the unit. Heat is removed by conduction, convection, and
radiation to the surrounding environment. The thermal data presented
is based on measurements taken in a set-up as shown in Figure7.
Figures 8 and 9 represent the test data. No
te that the airflow is parallel
to the long axis of the module as shown in Figure7 for the VPO
L5A-5-SIP.
The temperature at either location should not exceed 110 °C. The
output power of the module should not exceed the rated power for the
module (VO, set x IO, max).
The test setup shown in Figure 7 and E
UT
need to solder on 33mm x 40.38mm(1.300'' x
1.59'') test pcb.
Note that airflow is parallel to the long axis of the
module as shown in Fig7.
Figure 7. Temperature Measurement Location for SIP
±0
±0
±
±
For more information, please visit the product page.