RP112x

NO.EA-258-131024

11

measurement at the conditions below:

Measurement Conditions:

Standard Test Land Pattern

Environment

Mounting on Board (Wind velocity=0m/s)

Board Material

Glass cloth epoxy plastic (Double Layers)

Board Dimensions

40mm

× 40mm × 1.6mm

Copper Ratio

Top side: Approx. 50%, Back side: Approx. 50%

Through-hole

φ 0.5mm x 44pcs

Measurement Result:

(Ta=25

°C)

Standard Test Land Pattern

Free Air

Power Dissipation

380mW (Tjmax=125

°C)

475mW (Tjmax=150

°C)

150mW

θja=(125-25°C)/0.38W=263°C/W

θja=(125-25°C)/0.15W=667°C/W

Thermal Resistance

θjc=75°C/W

-

0

100

200

300

400

500

600

0

25

50

75

100

125

150

Ambient Temperature (ºC)

150

380

475

85

Free Air

Standard Test Land Pattern

Power Dissipation

Measurement Board Pattern

IC Mount Area (Unit: mm)

40

The above graph shows that the power dissipation of the package under the conditions of

Tjmax=125

°C and Tjmax=150°C. The use under the diagonal line in the graph might have an affect

on the ICs’ lifetime. Please use the ICs within the limited operating time and estimated years as

described below.

Operating Time

Estimated Years (4hrs/day)

13,000 hours

9 years