MC9S08SH8CTJ Datasheet, PDF (295/341 Pages) Freescale Semiconductor, Inc – MC9S08SH8 Datasheet

Appendix A Electrical Characteristics
A.4 Thermal Characteristics
This section provides information about operating temperature range, power dissipation, and package
thermal resistance. Power dissipation on I/O pins is usually small compared to the power dissipation in
on-chip logic and voltage regulator circuits, and it is user-determined rather than being controlled by the
MCU design. To take P_I/O into account in power calculations, determine the difference between actual pin
voltage and V_SS or V_DD and multiply by the pin current for each I/O pin. Except in cases of unusually high
pin current (heavy loads), the difference between pin voltage and V_SS or V_DD will be very small.
Table A-3. Thermal Characteristics
Num
C
Rating
Symbol
Value
Unit
1
— Operating temperature range (packaged)
C
T_A
M
T_L to T_H
–40 to 85
°C
–40 to 125
2
Maximum junction temperature
Thermal resistance ^1,2
Single-layer board
T_J
135
°C
3
D
8-pin NB SOIC
167
16-pin TSSOP
20-pin PDIP
123
θ_JA
°C/W
68
20-pin TSSOP
115
24-pin QFN
110
Thermal resistance^1,2
Four-layer board
8-pin NB SOIC
115
4
D
16-pin TSSOP
20-pin PDIP
20-pin TSSOP
75
°C/W
θ_JA
49
76
24-pin QFN
42
1 _{Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance, mounting}
site (board) temperature, ambient temperature, air flow, power dissipation of other components on the board,
and board thermal resistance.
2 _{Junction to Ambient Natural Convection}
MC9S08SH8 MCU Series Data Sheet, Rev. 3
Freescale Semiconductor
291