E
ESKEVIN
3/1301-BMR 637 02 Uen
225
Technical Specification
Approved
Checked
Date
Rev
EN/LZT 146 3R0e6feRre4nAceJuly 2008
PKM 4000D PINB Series
SEC/D (Julia You)
EYINGJI
2007-12-10
B
© Ericsson Power Modules AB
DC/DC converters, Input 36-75 V, Output 40 A/132 W
Operating information continued
Thermal Consideration
Parallel Operation
General
The PKM 4000DSeries DC/DC converters can be paralleled
for redundancy if external o-ring diodes are used in series
with the outputs. It is not recommended to parallel the PKM
4000D Series DC/DC converters for increased power without
using external current sharing circuits.
The PKM 4000DSeries DC/DC converters are designed to
operate in a variety of thermal environments, however
sufficient cooling should be provided to help ensure reliable
operation. Heat is removed by conduction, convection and
radiation to the surrounding environment. Increased airflow
enhances the heat transfer via convection. The available load
current vs. ambient air temperature and airflow at Vin =53 V
for each model is according to the information given under the
output section. The test is done in a wind tunnel with a cross
section of 305 x 305 mm, the DC/DC converter vertically
mounted on a 16 layer Pcb with a size of 254 x 254 mm, each
layer with 35 μm (1 oz) copper. Proper cooling can be verified
by measuring the temperature of selected devices. Peak
temperature can occur at positions P1 - P4. The temperature
at these positions should not exceed the recommended max
values.
See Design Note 006 for detailed information.
Remote Sense
All PKM 4000DSeries DC/DC converters have remote sense
that can be used to compensate for moderate amounts of
resistance in the distribution system and allow for voltage
regulation at the load or other selected point. The remote
sense lines will carry very little current and do not need a
large cross sectional area. However, the sense lines on the
Pcb should be located close to a ground trace or ground
plane. In a discrete wiring situation, the use of twisted pair
wires or other technique to reduce noise susceptibility is
highly recommended. The remote sense circuitry will
compensate for up to 10% voltage drop between the sense
voltage and the voltage at the output pins. The output voltage
and the remote sense voltage offset must be less than the
minimum over voltage trip point. If the remote sense is not
needed the —Sense should be connected to —Out and +Sense
should be connected to +Out.
Note that the max value is the absolute maximum rating
(non destruction) and that the electrical Output data is
guaranteed up to Tref +90°C.
See Design Note 019 for further information.
Position
P1
Device
Pcb
Designation
Tref
max value
110º C
P2
P3
P4
Mosfet
Tsurface
Tsurface
Tsurface
120º C
120º C
130º C
Over Temperature Protection (OTP)
Mosfet
The PKM 4000DSeries DC/DC converters are protected from
thermal overload by an internal over temperature shutdown
circuit. When the Pcb temperature (TC reference point)
exceeds the temperature trig point (120 °C) for the OTP
circuit the converter will cut down output power. The
converter will go into hiccup mode until safe operational
temperature is restored.
Transformer
Over Voltage Protection (OVP)
The PKM 4000DSeries DC/DC converters include output
overvoltage protection. In the event of an overvoltage
condition due to malfunction in the voltage monitoring
circuits, the converter's PWM will automatically dictate
minimum duty-cycle thus reducing the output voltage to a
minimum.
Over Current Protection (OCP)
The PKM 4000DSeries DC/DC converters include current
limiting circuitry that allows them to withstand continuous
overloads or short circuit conditions on the output. The
output voltage will decrease towards zero for output currents
in excess of max output current (Iomax).
The converter will resume normal operation after removal of
the overload. The load distribution system should be
designed to carry the maximum output short circuit current
specified.
ERICSSON [ ERICSSON ]
