Datasheet

MPC8245 Integrated Processor Hardware Specifications, Rev. 10
Freescale Semiconductor 13
Electrical and Thermal Characteristics
4.4 Thermal Characteristics
Table 6 provides the package thermal characteristics for the MPC8245. For details, see Section 7.8,
“Thermal Management.”
4.5 AC Electrical Characteristics
After fabrication, functional parts are sorted by maximum processor core frequency as shown in Table 7
and tested for conformance to the AC specifications for that frequency. The processor core frequency is
determined by the bus (PCI_SYNC_IN) clock frequency and the settings of the PLL_CFG[0:4] signals.
Parts are sold by maximum processor core frequency. See Section 9, “Ordering Information,” for details
on ordering parts.
Table 6. Thermal Characteristics
Characteristic Symbol Value Unit Notes
Junction-to-ambient natural convection
(Single-layer board—1s)
R
θ
JA
16.1 °C/W 1, 2
Junction-to-ambient natural convection
(Four-layer board—2s2p)
R
θ
JMA
12.0 °C/W 1, 3
Junction-to-ambient (@200 ft/min)
(Single-layer board—1s)
R
θ
JMA
11.6 °C/W 1, 3
Junction-to-ambient (@200 ft/min)
(Four layer board—2s2p)
R
θ
JMA
9.0 °C/W 1, 3
Junction-to-board R
θ
JB
4.8 °C/W 4
Junction-to-case R
θ
JC
1.8 °C/W 5
Junction-to-package top (natural convection)
Ψ
JT
1.0 °C/W 6
Notes:
1. Junction temperature is a function of die size, 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.
2. Per SEMI G38-87 and JEDEC JESD51-2 with the single-layer board horizontal.
3. Per JEDEC JESD51-6 with the board horizontal.
4. 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.
5. 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 used for case temperature.
6. Thermal characterization parameter indicating the temperature difference between the package top and the junction
temperature per JEDEC JESD51-2. When Greek letters are not available, the thermal characterization parameter is written
as Psi-JT.