Ericsson Internal
PRODUCT SPECIFICATION
4 (5)
Prepared (also subject responsible if other)
No.
ESKEVIN
3/1301-BMR 640 1401+ Uen
Approved
Checked
Date
Rev
Reference
SEC/D (Julia You)
EZYPING
2007-8-27
D
Thermal Consideration continued
Definition of reference temperature (Tref)
The reference temperature is used to monitor the temperature
limits of the product. Temperatures above maximum Tref are
not allowed and may cause degradation or permanent
damage to the product. Tref is also used to define the
temperature range for normal operating conditions.
Tref is defined by the design and used to guarantee safety
margins, proper operation and high reliability of the module.
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. E.g 85 % = 0.85
2. Find the thermal resistance (Rth) in the Thermal Resistance
graph found in the Output section for each model.
Calculate the temperature increase (ΔT).
ΔT = Rth x Pd
3. Max allowed ambient temperature is:
Max Tref - ΔT.
E.g PKR 4713 SI at 1m/s:
1. ((
) -
1) × 7 W = 1.24 W
2. 1.24 W × 14.0°C/W = 17.3°C
3. 110 °C — 17.3°C = max ambient temperature is 92.7°C
The actual temperature will be dependent on several factors
such as the PCB size, number of layers and direction of
airflow.
Connections
1
9
2
3
4
5
6
7
8
18 17 16 15 14 13 12 11 10
Pin
Designation
Function
1
Out 1
Output 1
2
Rtn
Output return
3
Out 21)
Output 2
4
NC
Not connected
5
NC
Not connected
6
NC
Not connected
7
NC
Not connected
8
Vadj
Output voltage adjust
9
NOR
Connection of Nominal Output
voltage Resistor
10
TOA
Turn-on/off input voltage adjust
11
RC
Remote control and turn-on/off
input voltage adjust
12
NC
Not connected
13
NC
Not connected
14
NC
Not connected
15
NC
Not connected
16
NC
Not connected
17
- In
Negative Input
18
+In
Positive input
1) Only for duals.
1
0.85
E
PKR 4000 series
DC/DC converters, Input 36-75 V, Output up to 1.5 A/7 W
EN/LZT 146 302 R6E September 2007
Ericsson Power Modules AB
Technical Specication
E
PKR 4000 series
DC/DC converters, Input 36-75 V, Output up to 1.5 A/7 W
EN/LZT 146 302 R6F November 2007
Ericsson Power Modules AB
Technical Specication
E
PKR 4000 series
DC/DC converters, Input 36-75 V, Output up to 1.5 A/7 W
EN/LZT 146 302 R6G November 2008
Ericsson Power Modules AB
Technical Specication
29