2.4.4 Safe Power Operating Condition Check of the Previous Example

Calculations:

• PI/O = Σ (({VDDIOx – VOH} x IOH) + Σ (VOL x IOL)) + (3.3V * VUSB3V3_0 IDD) + (3.3V * VUSB3V3_1 IDD)

  = ((3.3V – 2.4V) * 8 mA) + (0.4V * 16 mA) + (3.3V * 3.1 mA)

  = 23.83 mW (I/O Power, PI/O)

• PINTERNAL = PI/O + (VDDx * (Σ sum of all active VDDx_IDD peripheral currents)) +

  (1.8v x ((Σ Sum of all active CORE_IDD peripheral currents) + CPU_IDDREG))

  = 23.83 mW + (3.3V * 14.3 mA) + (1.8 * 378.5 mA)

  = 23.83 mW + 47.19 mW + 681.3 mW

  = 752.32 mW (CPU PD)

• PDMAX = (TJ – TA) / θJA package
• PDMAX = (TJ – TA) / θJA package

  = (125°C -85°C) / 23.7 °C/W

  = 1.69 Watts (Package PDMax)

Rule Cross Check:

• PINTERNAL ≤ PDMAX

  1.243W ≤ 1.69 W(max) = Application within Safe Power conditions. Success.

• Total VREG_SWn CORE_IDD = 281.5 mA.

  281.5mA ≤ 341mA(max) = Application within Safe Power conditions. Success.