FEDL22660-01
ML22660
■
Limitation on the operation time (Playback operating time)
This LSI operating temperature is 85
O
C (max). But the average ambient temperature at 1W playback (8ohm drive) for 10
years in the reliability design is Ta=65
O
C. (max (the package heat resistance θja=31.58 [
O
C/W]))
When this LSI operates 1W playback (8ohm drive) consecutively, the product life changes by the package temperature rise
by the consumption. This limitation does not matter in the state that a speaker amplifier does not play.
The factors to decide the operation time (playback operating time) are the average ambient temperature (Ta), playback Watts
(at the speaker drive mode), the soldering area ratio, and so on. In addition, the limitation on the operation time changes by
the heat designs of the board.
■
Package Heat Resistance Value (Reference Value)
(θja)
The following table is the package heat resistance value θja (reference value).
This value changes the condition of the board (size, layer number, and so on).
Board
θja
Ψjc
Ψjb
Condition
JEDEC 4layers
*1
（
W/L/t
＝
76.2/114.5/1.6
（
mm
））
31.58[
O
C/W]
0.57[
O
C/W]
11.64[
O
C/W]
Air cooling condition: No wind
(0m/s)
JEDEC 2layers
*2
（
W/L/t
＝
76.2/114.5/1.6
（
mm
））
37.77[
O
C/W]
0.61[
O
C/W]
12.43[
O
C/W]
the soldering area ratio
*3
：
100%
*1 : The wiring density : 1st layer(Top) 60% / 2nd layer 100% / 3rd layer 100% / 4th layer(Bottom) 60%.
*2 : The wiring density : 1st layer(Top) 60% / 2nd layer(Bottom) 100%.
*3 : The soldering area ratio is the ratio that the heat sink area of this LSI and a land pattern on the board are soldered. 100%
mean that the heat sink area of this LSI is completely soldered to the land pattern on the board. About the land pattern on the
board, be sure to refer to the next clause (Package Dimensions).
The definition of each temperature is shown below.
Take measures to dissipate heat on the mounting board so that the maximum junction temperature does not exceed 125
O
C.
Mounting board
1mm
Tb
Tc
Tj
Ta
105/116
Summary of Contents for LAPIS Semiconductor ML22660
Page 107: ...FEDL22660 01 ML22660 107 116 ...
