Datasheet

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TSZ02201-0RFR0G200530-1-2

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6.July.2015 Rev.001

TSZ22111･15･001

LM393xxx

LM2903xx

LM339xx

LM2901xx

Power Dissipation

consumes power, it heats up, causing its temperature to be higher than the ambient temperature. The allowable

temperature that the IC can accept is limited. This depends on the circuit configuration, manufacturing process, and

consumable power.

Power dissipation is determined by the allowable temperature within the IC (maximum junction temperature) and the

thermal resistance of the package used (heat dissipation capability). Maximum junction temperature is typically equal to the

maximum storage temperature. The heat generated through the consumption of power by the IC radiates from the mold

capability. Similarly, the temperature of an IC inside its package can be estimated by thermal resistance.

Figure 51(a) shows the model of the thermal resistance of a package. The equation below shows how to compute for the

°C/W

The Derating curve in Figure 51(b) indicates the power that the IC can consume with reference to ambient temperature.

Power consumption of the IC begins to attenuate at certain temperatures. This gradient is determined by Thermal

wind velocity, etc. This may also vary even when the same package is used. Thermal reduction curve indicates a reference

value measured at a specified condition. Figure 51(c) and (d) shows an example of the derating curve for LM393xxx,

LM2903xx, LM339xx, and LM2901xx.

(Note 21)

(Note 22)

(Note 23)

(Note 24)

(Note 25)

Unit

5.4

5.0

4.7

8.2

6.8

mW/°C

Power dissipation is the value when FR4 glass epoxy board 70mm ×70mm ×1.6mm (cooper foil area below 3%) is mounted.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0

25

50

75

100 125

150

Ambient Temperature [°C]

0.0

0.2

0.4

0.6

0.8

1.0

0

25

50

75

100 125 150

Ambient Temperature [°C]

Figure 51. Thermal Resistance and Derating Curve

(c) LM393xxx/LM2903xx

(a) Thermal Resistance

(b) Derating Curve

Power dissipation of LSI [W]

050

75

100

125

150

25

P1

P2

(d) LM339xx/LM2901xx

85

LM393PT

(Note 22)

LM393WPT

(Note 22)

LM2903PT

(Note 22)

LM2903DT

(Note 21)

LM393DT

(Note 21)

LM393WDT

(Note 21)

LM393ST

(Note 23)

85

LM339DT

(Note 24)

LM339PT

(Note 25)

LM2901DT

(Note 24)

LM2901PT

(Note 25)