PKM2515EPI Ericsson Power Modules, PKM2515EPI Datasheet - Page 22

• Manufacturer Part Number: PKM2515EPI
• Description: DC/DC Converters & Regulators 15Vdc 3.3A Isolated Input 18-36V 50W
• Manufacturer: Ericsson Power Modules
• Series: PKM-Er

Specifications of PKM2515EPI

• Output Power: 50 W
• Input Voltage Range: 18 V to 36 V
• Number Of Outputs: 1
• Output Voltage (channel 1): 15 V
• Output Current (channel 1): 3.3 A
• Package / Case Size: Quarter Brick
• Output Type: Isolated
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Over Temperature Protection (OTP)
The PKM 2000E Series DC/DC converters are protected
from thermal overload by an internal over temperature
shutdown circuit . When the PCB temperature adjacent to
the PWM control circuit exceeds 120 ºC the converter will
shut down immediately . The converter will make continuos
attempts to start up (non-latching mode) and resume normal
operation automatically when the temperature has dropped
>10ºC below the temperature threshold .
Operating Information
PKM 2000E PI Datasheet
Current Limit Protection
The PKM 2000E Series DC/DC converters include current
limiting circuitry that allows them to withstand continuous
overloads or short circuit conditions on the output . The out-
put 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 .
Over Voltage Protection (OVP)
The PKM 2000E Series DC/DC converters have output over-
voltage protection . In the event of an overvoltage condition,
the converter will shut down immediately . The converter will
make continuous attempts to start up (non-latching mode)
and resume normal operation automatically .
Input And Output Impedance
The impedance of both the power source and the load will
interact with the impedance of the DC/DC converter . It is
most important to have a ratio between L and C as low as
possible, i .e . a low characteristic impedance, both at the in-
put and output, as the converters have a low energy storage
capability . The PKM 2000E Series DC/DC converters have
been designed to be completely stable without the need
for external capacitors on the input or the output circuits .
The performance in some applications can be enhanced by
addition of external capacitance as described under maxi-
mum capacitive load . If the distribution of the input voltage
source to the converter contains significant inductance, the
addition of a 100µF capacitor across the input of the con-
verter will help insure stability . This capacitor is not required
when powering the DC/DC converter from a low impedance
source with short, low inductance, input power leads .

Maximum Capacitive Load
Parallel Operation
The PKM 2000E Series 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
2000E Series DC/DC converters for increased power without
using external current sharing circuits .
When powering loads with significant dynamic current
requirements, the voltage regulation at the load can be
improved by addition of decoupling capacitance at the load .
The most affective technique is to locate low ESR ceramic
capacitors as close to the load as possible, using several
capacitors to lower the effective ESR . These ceramic ca-
pacitors will handle short duration high-frequency compo-
nents of dynamic load changes . In addition, higher values of
electrolytic capacitors should be used to handle the mid-fre-
quency components . It is equally important to use good de-
sign practise when configuring the DC distribution system .
Low resistance and low inductance PCB (printed circuit
board) layouts and cabling should be used . Remember that
when using remote sensing, all resistance, inductance and
capacitance of the distribution system is within the feed-
back loop of the converter . This can affect on the convert-
ers compensation and the resulting stability and dynamic
response performance . As a “rule of thumb”, 100µF/A of
output current can be used without any additional analysis .
For example with a 25A converter, values of decoupling
capacitance up to 2500 µF can be used without regard to
stability . With larger values of capacitance, the load transient
recovery time can exceed the specified value . As much of
the capacitance as possible should be outside the remote
sensing loop and close to the load . The absolute maximum
value of output capacitance is 10 000 µF . For values larger
than this, please contact your local Ericsson Power Modules
representative .
EN/LZT 146 050 R4A © Ericsson Power Modules, March 2007