Thermal Characteristics

Table 1. Thermal Characteristics
Symbol Description Typ. Units Conditions
θJA Thermal Resistance Junction to Ambient (Thermal simulation, no airflow) 58 °C/W 14-pin SOIC package (SL)
44 °C/W 20-pin SOIC package (SO)
79.7 °C/W 20-pin VQFP package (REB)
  1. 1.Power dissipation is calculated as follows:

    PDIS = VDD × {IDD - Σ IOH} + Σ {(VDD - VOH) × IOH} + Σ (VOI × IOL)

  2. 2.Internal Power Dissipation is calculated as follows: PINTERNAL = IDD × VDD, where IDD is current to run the chip alone without driving any load on the output pins.
  3. 3.Derated Power is calculated as follows: PDER = PDMAX (TJ-TA)/θJA, where TA = Ambient Temperature, TJ = Junction Temperature.