mpc755ed Freescale Semiconductor, Inc, mpc755ed Datasheet - Page 9

• Manufacturer Part Number: mpc755ed
• Description: Risc Microprocessor Hardware Specifications
• Manufacturer: Freescale Semiconductor, Inc

The MPC755 incorporates a thermal management assist unit (TAU) composed of a thermal sensor,
digital-to-analog converter, comparator, control logic, and dedicated special-purpose registers (SPRs). See
the MPC750 RISC Microprocessor Family User’s Manual for more information on the use of this feature.
Specifications for the thermal sensor portion of the TAU are found in
Freescale Semiconductor
Junction-to-ambient thermal resistance, natural
convection
Junction-to-ambient thermal resistance, natural
convection, four-layer (2s2p) board
Junction-to-ambient thermal resistance, 200 ft/min
airflow, single-layer (1s) board
Junction-to-ambient thermal resistance, 200 ft/min
airflow, four-layer (2s2p) board
Junction-to-board thermal resistance
Junction-to-case thermal resistance
Notes:
1. Junction temperature is a function of on-chip power dissipation, package thermal resistance, mounting site (board)
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
5. Thermal resistance between the die and the case top surface as measured by the cold plate method (MIL SPEC-883 Method
6. Refer to
temperature, ambient temperature, air flow, power dissipation of other components on the board, and board thermal
resistance.
the top surface of the board near the package.
1012.1) with the calculated case temperature. The actual value of R
Section 8.8, “Thermal Management Information,”
Characteristic
MPC755 RISC Microprocessor Hardware Specifications, Rev. 8
Table 4. Package Thermal Characteristics
Symbol
R
R
R
R
R
R
θ
θ
θ
θ
θ
θ
JMA
JMA
JMA
JC
JA
JB
for more details about thermal management.
MPC755
CBGA
θJC
<0.1
24
17
18
14
8
for the part is less than 0.1°C/W.
MPC755
Table
PBGA
Value
<0.1
31
25
25
21
17
6
Electrical and Thermal Characteristics
5.
MPC745
PBGA
<0.1
34
26
27
22
17
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
Unit
Notes
1, 2
1, 3
1, 3
1, 3
4
5
9