INSTRUCTION MANUAL
CCG 1R5/3
TDK-Lambda
<Page>
21/36
Fig.7-2 Output Current vs. Ambient Temperature Measurement Method (for forced cooling)
Fig.7-1 Output Current vs. Ambient Temperature Measurement Method (for convection cooling)
(2) Output Current vs. Ambient Temperature Measurement Method (for forced cooling)
7.
Output Derating
7-1. Output Derating Measurement Method
There is no restriction on mounting direction but there should be enough consideration for airflow so
that heat dose not accumulate around the power supply vicinity. Determine external components
configuration and mounting direction on PCB such that air could flow around the power supply at
forced cooling and conventional cooling. The derating of the output current is necessary when the
ambient temperature is high. (See
「
7-2. Output Derating Curve
」
.)
Measurement method of Output Current vs. Ambient Temperature is according to Fig.7-1 and Fig.7-2.
When mounting on actual system, do actual measurement based on measurement points shown in
Fig.7-1 and Fig.7-2. Moreover take note that component temperature shown in Fig.7-3 not to exceed
the criterion value.
(1) Output Current vs. Ambient Temperature Measurement Method (for convection cooling)
PCB
Power Supply
Ambient temperature measurement point
CL
76
m
m
12.7mm
Wind
Tunnel
Power Supply
Ambient temperature
and air velocity
measurement point
25.4mm
Airflow
Airflow
Top
view
-Vin
+Vin
RC
-Vo
+Vo
TRM,COM
PCB
76mm
12
.7
m
m
