Datasheet

LXDC2UR series
Micro DC-DC converter
7
Dec 2014
6-3 Thermal and Current De-rating Information
The following figure shows the power dissipation and temperature rise characteristics example. These data are
measured on Murata’s evaluation board of this device at no air-flow condition.
The output current of the device may need to be de-rated if it is operated in a high ambient temperature or in a
continuous power delivering application. The amount of current de-rating is highly dependent on the
environmental thermal conditions, i.e. PCB design, nearby components or effective air flows. Care should
especially be taken in applications where the device temperature exceeds 85
o
C.
The IC temperature of the device must be kept lower than the maximum rating of 125
o
C. It is generally
recommended to take an appropriate de-rating to IC temperature for a reliable operation. A general de-rating for
the temperature of semiconductor is 80%.
MLCC capacitor’s reliability and lifetime are also depending on temperature and applied voltage stress. Higher
temperature and/or higher voltage cause shorter lifetime of MLCC, and the degradation can be described by the
Arrhenius model. The most critical parameter of the degradation is IR (Insulation Resistance). The below figure
shows MLCC’s B1 life based on a failure rate reaching 1%. It should be noted that wear-out mechanisms in
MLCC capacitor is not reversible but cumulative over time.
0
5
10
15
20
25
30
35
0 50 100 150 200 250
ΔT [℃ ]
Power dissipation [mW]
Loss-ΔT Characteristics (Vin=3.6V, Vo=1.8V)
0
50
100
150
200
250
0 100 200 300 400 500 600
Power dissipation [mW]
Io [mA]
Io - Loss Characteristics (Vin=3.6V, Vo=1.8V)