mpc855t Freescale Semiconductor, Inc, mpc855t Datasheet - Page 9

• Manufacturer Part Number: mpc855t
• Description: Mpc855t Powerquicc Integrated Communications Processor
• Manufacturer: Freescale Semiconductor, Inc

Table 4
Freescale Semiconductor
1
2
3
4
5
6
Mold Compound Thickness
Junction-to-ambient
Junction-to-board
Junction-to-case
Junction-to-package top
Junction temperature is a function of on-chip power dissipation, package thermal resistance, mounting site (board)
temperature, ambient temperature, airflow, power dissipation of other components on the board, and board thermal
resistance.
Per SEMI G38-87 and JEDEC JESD51-2 with the single-layer board horizontal.
Per JEDEC JESD51-6 with the board horizontal.
Thermal resistance between the die and the printed-circuit board per JEDEC JESD51-8. Board temperature is measured
on the top surface of the board near the package.
Indicates the average thermal resistance between the die and the case top surface as measured by the cold plate method
(MIL SPEC-883 Method 1012.1) with the cold plate temperature used for the case temperature. For exposed pad
packages where the pad would be expected to be soldered, junction-to-case thermal resistance is a simulated value from
the junction to the exposed pad without contact resistance.
Thermal characterization parameter indicating the temperature difference between the package top and the junction
temperature per JEDEC JESD51-2.
shows the thermal characteristics for the MPC860.
Rating
5
4
1
6
MPC860 PowerQUICC™ Family Hardware Specifications, Rev. 8
Natural convection
Airflow (200 ft/min)
Natural convection
Table 4. MPC860 Thermal Resistance Data
Environment
Single-layer board (1s)
Four-layer board (2s2p)
Single-layer board (1s)
Four-layer board (2s2p)
Symbol
R
R
R
R
R
R
θJMA
θJMA
θJMA
Ψ
θJA
θJC
θJB
JT
2
3
3
3
MPC860P
0.85
ZP
34
22
27
18
14
6
2
Thermal Characteristics
MPC860P
ZQ / VR
1.15
34
22
27
18
13
8
2
•C/W
Unit
mm
C/W
9