PKY4716PI Ericsson Power Modules, PKY4716PI Datasheet - Page 14

• Manufacturer Part Number: PKY4716PI
• Manufacturer: Ericsson Power Modules
• Type: Step Downr

Specifications of PKY4716PI

• Output Current: 25 A
• Output Voltage: 28 V
• Input Voltage: 36 to 75 V
• Number Of Outputs: 1
• Output Power: 700 W
• Switching Regulator: Yes

Operating information
Input Voltage
The input voltage range 36 to 75Vdc meets the requirements
of the European Telecom Standard ETS 300 132-2 for normal
input voltage range in –48 and –60 Vdc systems, -40.5 to -
57.0 V and –50.0 to -72 V respectively.
At input voltages exceeding 75 V, the power loss will be higher
than at normal input voltage and T
absolute max +100°C. The absolute maximum continuous
input voltage is 100 Vdc.
Turn-off Input Voltage
The products monitor the input voltage and will turn on and
turn off at predetermined levels.
The minimum hysteresis between turn on and turn off input
voltage is 1V.
Remote Control (RC)
The modules are equipped with a remote On/Off control
function. An optocoupler in the remote control circuit provides
a galvanic isolation (1500V DC minimum) between the
remote control pins and the rest of the module’s circuity.
Positive and negative RC logic options are available.
Cycling (Off and On sequence) of the RC input will restart the
module if latched after activation of the output overvoltage
protection function.
The standard version has a “positive logic” remote control and
the module will be off until a sufficient current between the RC
pins is provided.
The figure above presents an example of a circuit which turns
on the standard version module. The minimum current to
guarantee the activation of the RC input is 1.5mA. The
minimum activation voltage over the RC pins is 5.0V. To
guarantee that the RC input is not activated, the current must
be lower than 50µA or the voltage lower than 1.3V.
Input and Output Impedance
The impedance of both the input source and the load will
interact with the impedance of the product. It is important that
the input source has low characteristic impedance. The
products are designed for stable operation without external
capacitors connected to the input or output. The performance
in some applications can be enhanced by addition of external
capacitance as described under External Decoupling
Capacitors.
Prepared (also subject responsible if other)
ESECZHW
Approved
SEC/D (Julia You)
PKY 4000 PI series
DC/DC converters, Input 36-75 V, Output up to 25 A/700 W
P1
must be limited to
Checked
ECHWANG
PRODUCT SPECIFICATION
No.
3/1301- BMR 638/1 Uen
Date
2008-10-9
If the input voltage source contains significant inductance, the
addition of a 220 µF/100V capacitor across the input of the
product will ensure stable operation. The capacitor is not
required when powering the product from an input source with
an inductance below 10 µH. The minimum required
capacitance value depends on the output power and the input
voltage. The higher output power the higher input capacitance
is needed. Approximately doubled capacitance value is
required for a 24 V input voltage source compared to a 48V
input voltage source.
External Decoupling Capacitors
When powering loads with significant dynamic current
requirements, the voltage regulation at the point of load can
be improved by addition of decoupling capacitors at the load.
The most effective technique is to locate low ESR ceramic and
electrolytic capacitors as close to the load as possible, using
several parallel capacitors to lower the effective ESR. The
ceramic capacitors will handle high-frequency dynamic load
changes while the electrolytic capacitors are used to handle
low frequency dynamic load changes. It is equally important to
use low resistance and low inductance PCB layouts and
cabling.
External decoupling capacitors will become part of the
product’s control loop. The control loop is optimized for a wide
range of external capacitance and the maximum
recommended value that could be used without any additional
analysis is found in the Electrical specification.
The ESR of the capacitors is a very important parameter.
Stable operation is guaranteed with a verified ESR value of
>10 mΩ across the output connections.
For further information please contact your local Ericsson
Power Modules representative.
Output Voltage Adjust (V
The products have an Output Voltage Adjust pin (V
pin can be used to adjust the output voltage above or below
Output voltage initial setting.
When increasing the output voltage, the voltage at the output
pins (including any remote sense compensation ) must be
kept below the threshold of the over voltage protection, (OVP)
to prevent the product from shutting down. At increased output
voltages the maximum power rating of the product remains the
same, and the max output current must be decreased
correspondingly. When Vout is 15V,the max output current is
25A for PKY4716,that is to say,the power is 375W.
To increase the voltage the resistor should be connected
between the V
Output voltage adjust function is according to information
given under the Output section for the respective product.
To decrease the output voltage, the resistor should be
connected between the V
adj
pin and +Sense pin. The resistor value of the
Technical Specifi cation
EN/LZT 146 380 R2A Oct 2008
© Ericsson Power Modules AB
Rev
C
adj
adj
pin and –Sense pin.
)
Reference
adj
). This
2 (6)
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