stk672-640b-e Sanyo Semiconductor Corporation, stk672-640b-e Datasheet - Page 20

• Manufacturer Part Number: stk672-640b-e
• Description: 2-phase Stepping Motor Driver
• Manufacturer: Sanyo Semiconductor Corporation

6. Mitigated Curve of Package Power Loss, PdPK, vs. Ambient Temperature, Ta
Package power loss, PdPK, refers to the average internal power loss, PdAV, allowable without a heat sink.
The figure below represents the allowable power loss, PdPK, vs. fluctuations in the ambient temperature, Ta.
Power loss of up to 3.1W is allowable at Ta=25°C, and of up to 1.75W at Ta=60°C.
* The package thermal resistance θc-a is 25.8°C/W.
Figure 2 Substrate temperature rise, ΔTc (no heat sink) - Internal average power dissipation, PdAV
Allowable power dissipation, PdPK(no heat sink) - Ambient temperature, Ta
Figure 3 Heat sink area (Board thickness: 2mm) - θc-a
100
1.0
10
3.5
3.0
2.5
2.0
1.5
1.0
0.5
80
70
60
50
40
30
20
10
7
5
3
2
7
5
3
2
0
0
10
0
0
Hybrid IC internal average power dissipation, PdAV - W
0.5
2
20
STK672-640B-E
3
Ambient temperature,Ta - °C
1.0
Heat sink area, S - cm
40
5
ΔTc - PdAV
PdPK - Ta
θc-a - S
1.5
7
100
60
2.0
2
80
2
2.5
3
100
3.0
5
7
ITF02554
ITF02553
ITF02511
1000
120
3.5
No. A1739-20/24