LT1302/LT1302-5
APPLICATIONS INFORMATION
As an example, consider a boost converter with the
following specifications:
VIN = 3V
VOUT = 6V
IOUT = 700mA
Total power loss in the LT1302, assuming R = 0.15Ω and
VD = 0.45V, is:
( ) ( ) ( )( ) PD =
2
700mA 0.15Ω
2
6 + 0.45
3
−
0.7×
6×
3
0.15
−
3
−
6 + 0.45
0.7× 6 × 0.15
3
+
0.7
6 + 0.45 − 3
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= 223mW + 89mW = 312mW
Using the CS8 package with 100 sq. mm topside and
backside heat sinking:
∆T = (312mW)(84°C/W) = 25.9°C rise
With the N8 package:
∆T = 31.2°C
At a 70°C ambient, die temperature would be 101.2°C.
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