PKU4513PI Ericsson Power Modules, PKU4513PI Datasheet - Page 32

• Manufacturer Part Number: PKU4513PI
• Description: DC/DC Converters & Regulators 12Vdc 4.2A Isolated Input 36-75V 50W
• Manufacturer: Ericsson Power Modules
• Series: PKUr

Specifications of PKU4513PI

• Output Power: 50 W
• Input Voltage Range: 36 V to 75 V
• Number Of Outputs: 1
• Output Voltage (channel 1): 12 V
• Output Current (channel 1): 4.2 A
• Isolation Voltage: 1.5 KV
• Package / Case Size: Sixteenth Brick
• Output Type: Isolated
• Product: Isolated
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Thermal Consideration
General
The converters are designed to operate in different thermal
environments and sufficient cooling must be provided to
ensure reliable operation.
Cooling is achieved mainly by conduction, from the pins to
the host board, and convection, which is dependent on the
airflow across the converter. Increased airflow enhances the
cooling of the converter.
The Output Current Derating graph found in the Output
section for each model provides the available output current
vs. ambient air temperature and air velocity at V
The DC/DC converter is tested on a 254 x 254 mm,
35 µm (1 oz), 8-layer test board mounted vertically in a wind
tunnel with a cross-section of 305 x 305 mm.
Proper cooling of the DC/DC converter can be verified by
measuring the temperature at positions P1. The temperature
at these positions should not exceed the max values provided
in the table below.
See Design Note 019 for further information.
Definition of reference temperature (T
The reference temperature is used to monitor the temperature
limits of the product. Temperatures above maximum T
not allowed and may cause degradation or permanent
damage to the product. T
temperature range for normal operating conditions.
T
margins, proper operation and high reliability of the module.
Position
P
Prepared (also subject responsible if other)
EJUNGYA
Approved
SEC/D (Julia You)
PKU 4000 Series
DC/DC converters, Input 36-75 V, Output 25 A/50 W
ref
1
is defined by the design and used to guarantee safety
Device
Mosfet
ref
Designation
T
is also used to define the
P
ref
1
ref
)
Max value
120ºC
in
Checked
EQUENXU
= 53 V.
ref
are
Ambient Temperature Calculation
By using the thermal resistance the maximum allowed
ambient temperature can be calculated.
1. The power loss is calculated by using the formula
((1/η) - 1) × output power = power losses (Pd).
η = efficiency of converter. For example 89.2 % = 0.892
2. Find the thermal resistance (R
graph found in the Output section for each model.
Calculate the temperature increase (∆T).
3. Max allowed ambient temperature is:
Max T
Example PKU 4510 (@ V
1.
2. 5.99 W × 9.2°C/W = 55.1°C
3. 120 °C — 55.1°C = max ambient temperature is 64.9°C
The actual temperature will be dependent on several factors
such as the PCB size, number of layers and direction of
airflow.
PRODUCT SPECIFICATION
No.
3/1301-BMR 602 Uen
Date
2008-6-10
∆T = Rt
((
0.892
ref
1
h
- ∆T.
x P
) -
d
1) × 49.5 W = 5.99 W
Technical Specifi cation
EN/LZT 146 308 R4B July 2008
© Ericsson Power Modules AB
Rev
F
I
53 V &15 A) at 1 m/s:
Reference
th
) in the Thermal Resistance
4 (6)
32