LT1355/LT1356
APPLICATIONS INFORMATION
Power Dissipation
The LT1355/LT1356 combine high speed and large output
drive in small packages. Because of the wide supply
voltage range, it is possible to exceed the maximum
junction temperature under certain conditions. Maximum
junction temperature (TJ) is calculated from the ambient
temperature (TA) and power dissipation (PD) as follows:
LT1355CN8: TJ = TA + (PD x 130°C/W)
LT1355CS8: TJ = TA + (PD x 190°C/W)
LT1356CN: TJ = TA + (PD x 110°C/W)
LT1356CS: TJ = TA + (PD x 150°C/W)
Worst case power dissipation occurs at the maximum
supply current and when the output voltage is at 1/2 of
either supply voltage (or the maximum swing if less than
1/2 supply voltage). For each amplifier PDMAX is:
PDMAX = (V+ – V–)(ISMAX) + (V+/2)2/RL
Example: LT1356 in S16 at 70°C, VS = ±15V, RL = 1k
PDMAX = (30V)(1.45mA) + (7.5V)2/1kW = 99.8mW
TJMAX = 70°C + (4 × 99.8mW)(150°C/W) = 130°C
W
W
SI PLIFIED SCHE ATIC
V+
R1
800Ω
+IN
RC
–IN
OUT
C
CC
V–
1355/1356 SS01
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