Safety
Electrical Data
The PKF 4211A I DC/DC power module is designed in accordance
with EN 60 950, Safety of information technology equipment including
electrical business equipment. The PKF power modules are recognized
by UL and meet the applicable requirements in UL 1950 Safety of
information technology equipment, the applicable Canadian safety
requirements and UL 1012 Standard for power supplies.
Fundamental circuit diagram, Single output
The DC/DC power module shall be installed in an end-use equip-
ment and considerations should be given to measuring the case
temperature to comply with TCmax when in operation. Abnormal
component tests are conducted with the input protected by an
external 15 A fuse. The need for repeating these tests in the end-
use appliance shall be considered if installed in a circuit having
higher rated devices.
When the supply to the DC/DC power module meets all the re-
quirements for SELV (<60Vdc), the output is considered to remain
within SELV limits (level 3). The isolation is an operational insula-
tion in accordance with EN 60 950.
The DC/DC power module is intended to be supplied by isolated
secondary circuitry and shall be installed in compliance with the
requirements of the ultimate application. If they are connected to
a 60 V DC system reinforced insulation must be provided in the
power supply that isolates the input from the mains. Single fault
testing in the power supply must be performed in combination
with the DC/DC power module to demonstrate that the output
meets the requirement for SELV. One pole of the input and one
pole of the output is to be grounded or both are to be kept float-
ing. The terminal pins are only intended for connection to mating
connectors of internal wiring inside the end-use equipment.
These DC/DC power modules may be used in telephone equipment
in accordance with paragraph 34 A.1 of UL 1459 (Standard for
Telephone Equipment, second edition).
Transient input voltage
Single voltage pulse at +25°C ambient temperature.
The galvanic isolation is verified in an electric strength test. Test
voltage (VISO) between input and output is 1,500 Vdc for 60 s. In
production the test duration may be decreased to 1 s.
The capacitor between input and output has a value of 1 nF and
the leakage current is less than 1µA @ 53 Vdc.
The case is designed in non-conductive epoxy. Its flammability
rating meets UL 94V-0. The oxygen index is 34%.
EN/LZT 146 79 R1A ©Ericsson Microelectronics AB, June 2001
3
ERICSSON [ ERICSSON ]
