STK6103 Datasheet, PDF (10/11 Pages) Sanyo Semicon Device – DC 3-phase Brushless Motor Driver (Output Current 3A)

STK6103
(2) Thermal radiation design
Actual thermal radiation design requires determination of the IC internal average power dissipation Pd from the
motor phase current Io (Fig. 9). Pd is then used to determine the thermal resistance for the radiator from the
following expression.
θc – a =
Tc max – Ta
Pd
(°C/W)
where Tc max = 105°C
Ta = ambient temperature
With a 2.0 mm radiation plate, the required area can be determined from Fig. 10. Note that substrate temperature
will vary widely with set internal air temperature, and Tc for the mounted state must be 105°C max.
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