Datasheet

Data Sheet
22
Safety and Installation Instruction
Isolation Consideration
ThePXD20-xxSxx series features 1.6k Volt DC isolation from inputto output, input tocase, and output to case.The
inputto output resistance is greater than 10
9
ohms. Nevertheless,if the system using the power module needs safety
agency approval, certain rules must be followed inthe design of the system using the model. In particular, all of the
creepage and clearance requirements of the end-use safety requirement must be observed.These documents
include UL-60950-1, EN60950-1 and CSA22.2-960, although specific applications may have other or additional
requirements.
Fusing Consideration
Caution: This power module is not internallyfused.An inputlinefuse must always be used.This encapsulated power
module can be used in a wide variety of applications,ranging fromsimple stand-alone operation or an integrated part
of a sophisticated power architecture. For maximum flexibility, internalfusing is not included;however, to achieve
maximum safety and system protection, always use an input line fuse. The safety agencies require a slow-blow fuse
with maximum rating of 3A. Based on the information provided in this datasheet on inrush energyand maximum DC
inputcurrent, thesame type of fuse with lowerrating can be used. Refer to the fuse manufacturer’s data for further
information.
MTBF and Reliability
The MTBF of PXD20-xxSxxseries of DC/DCconvertershas been calculatedusing
1.MIL-HDBK-217F under the following conditions:
Nominal Input Voltage
Io = Io,max
Ta = 25°C ℃
Theresulting figure for MTBF is 6.842× 10
5
hours.
2.Bell-coreTR-NWT-000332 CaseI:
50% stress, Operating Temperature at 40°C ℃ (Ground fixed and controlledenvironment)
Theresulting figure for MTBF is 1.791× 10
6
hours.