MPC870 FREESCALE [Freescale Semiconductor, Inc], MPC870 Datasheet - Page 9

• Manufacturer Part Number: MPC870
• Description: Hardware Specifications
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Freescale Semiconductor
4 Thermal Characteristics
Table 4
1
2
3
4
5
6
5 Power Dissipation
Table 5
equal, and 2:1, where CPU frequency is twice bus speed.
1
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)
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
Indicates the average thermal resistance between the die and the case top surface as measured by the cold plate
Thermal characterization parameter indicating the temperature difference between the package top and the junction
Typical power dissipation is measured at V
temperature, ambient temperature, airflow, power dissipation of other components on the board, and board thermal
resistance.
measured on the top surface of the board near the package.
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.
temperature per JEDEC JESD51-2.
shows the thermal characteristics for the MPC875/870.
provides information on power dissipation. The modes are 1:1, where CPU and bus speeds are
Rating
5
4
Die Revision
1
6
0
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Table 4. MPC875/870 Thermal Resistance Data
MPC875/MPC870 Hardware Specifications, Rev. 3.0
Natural convection
Airflow (200 ft/min)
Natural convection
Airflow (200 ft/min)
Table 5. Power Dissipation (P
DDL
= V
Environment
DDSYN
Mode
Bus
1:1
2:1
Single-layer board (1s)
Four-layer board (2s2p)
Single-layer board (1s)
Four-layer board (2s2p)
= 1.8 V, and V
Frequency
133 MHz
66 MHz
80 MHz
DDH
D
)
is at 3.3 V.
Typical
310
350
430
Symbol
R
R
R
R
R
θJMA
R
θJMA
θJMA
Ψ
Ψ
1
θJA
θJC
θJB
JT
JT
2
3
3
3
Maximum
Thermal Characteristics
390
430
495
Value
43
29
36
26
20
10
2
2
2
°C/W
Unit
Unit
mW
mW
mW
9