STM32F031x4 STM32F031x6
Package information
7.7
Thermal characteristics
The maximum chip junction temperature (TJmax) must never exceed the values given in
Table 18: General operating conditions.
The maximum chip-junction temperature, TJ max, in degrees Celsius, may be calculated
using the following equation:
TJ max = TA max + (PD max x ΘJA)
Where:
• TA max is the maximum ambient temperature in °C,
• ΘJA is the package junction-to-ambient thermal resistance, in °C/W,
• PD max is the sum of PINT max and PI/O max (PD max = PINT max + PI/Omax),
• PINT max is the product of IDD and VDD, expressed in Watts. This is the maximum chip
internal power.
PI/O max represents the maximum power dissipation on output pins where:
PI/O max = Σ (VOL × IOL) + Σ ((VDDIOx – VOH) × IOH),
taking into account the actual VOL / IOL and VOH / IOH of the I/Os at low and high level in the
application.
Table 68. Package thermal characteristics
Symbol
Parameter
Thermal resistance junction-ambient
LQFP48 - 7 × 7 mm
Thermal resistance junction-ambient
UFQFPN32 - 5 × 5 mm
Thermal resistance junction-ambient
LQFP32 - 7 × 7 mm
ΘJA Thermal resistance junction-ambient
UFQFPN28 - 4 × 4 mm
Thermal resistance junction-ambient
WLCSP25 - 2.13 x 2.07 mm
Thermal resistance junction-ambient
TSSOP20 - 6.5 x 4.4 mm
Value
55
38
56
118
74
110
Unit
°C/W
7.7.1
Reference document
JESD51-2 Integrated Circuits Thermal Test Method Environment Conditions - Natural
Convection (Still Air). Available from www.jedec.org
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