ISL28118 Datasheet, PDF (19/23 Pages) Intersil Corporation – 40V Precision Single Supply Rail-to-Rail Output Low Power Operational Amplifiers

ISL28118, ISL28218
Power Dissipation
It is possible to exceed the +150°C maximum junction
temperatures under certain load and power supply
conditions. It is therefore important to calculate the
maximum junction temperature (T_JMAX) for all
applications to determine if power supply voltages, load
conditions, or package type need to be modified to
remain in the safe operating area. These parameters are
related using Equation 1:
T_JMAX = T_MAX + θ_JAxPD_MAXTOTAL
(EQ. 1)
where:
• P_DMAXTOTAL is the sum of the maximum power
dissipation of each amplifier in the package (PD_MAX)
• PD_MAX for each amplifier can be calculated using
Equation 2:
PD_MAX
=
V_S × I_qMAX + (V_S
-
V_OUTMAX
)
×
-^V----^O----^U----^T----^M-----^A----^X--
R_L
(EQ.2)
where:
• T_MAX = Maximum ambient temperature
• θ_JA = Thermal resistance of the package
• PD_MAX = Maximum power dissipation of 1 amplifier
• V_S = Total supply voltage
• I_qMAX = Maximum quiescent supply current of 1
amplifier
• V_OUTMAX = Maximum output voltage swing of the
application
• R_L = Load resistance
19
FN7532.1
November 22, 2010