R1155 Datasheet, PDF (22/26 Pages) RICOH electronics devices division – 150 mA 24 V Input High Voltage Regulator

POWER DISSIPATION
SOT-23-5
Ver. A
Power Dissipation (PD) of the package is dependent on PCB material, layout, and environmental conditions.
The following conditions are used in this measurement. This data is taken from SOT-23-6.
Measurement Conditions
Environment
Board Material
Board Dimensions
Copper Ratio
Through-holes
Standard Land Pattern
Mounting on Board (Wind Velocity = 0 m/s)
Glass Cloth Epoxy Plastic (Double-sided)
40 mm x 40 mm x 1.6 mm
Top-side: Approx. 50%, Back-side: Approx. 50%
 0.5 mm x 44 pcs
Measurement Result
Power Dissipation
Thermal Resistance
Standard Land Pattern
420 mW
ja = (125 - 25C) / 0.42 W = 238C/W
(Ta = 25C, Tjmax = 125C)
Free Air
250 mW
400C/W
600
500
420
400
On Board
Free Air
300 ₂₅₀
200
100
0
105
0
25 50 75 100 125 150
Ambient Temperature (°C)
Power Dissipation (mW) vs. Temperature (°C)
40
IC Mount Area (Unit: mm)
Measurement Board Pattern
i