MPC880ZP133 Freescale Semiconductor, MPC880ZP133 Datasheet - Page 13

• Manufacturer Part Number: MPC880ZP133
• Description: IC MPU POWERQUICC 133MHZ 357PBGA
• Manufacturer: Freescale Semiconductor

Specifications of MPC880ZP133

• Processor Type: MPC8xx PowerQUICC 32-Bit
• Speed: 133MHz
• Voltage: 3.3V
• Mounting Type: Surface Mount
• Package / Case: 357-PBGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -

7.2
Historically, thermal resistance has frequently been expressed as the sum of a junction-to-case thermal
resistance and a case-to-ambient thermal resistance:
where:
R
affect the case-to-ambient thermal resistance, R
the device, add a heat sink, change the mounting arrangement on the printed-circuit board, or change the
thermal dissipation on the printed-circuit board surrounding the device. This thermal model is most useful
for ceramic packages with heat sinks where some 90% of the heat flows through the case and the heat sink
to the ambient environment. For most packages, a better model is required.
7.3
A simple package thermal model that has demonstrated reasonable accuracy (about 20%) is a two-resistor
model consisting of a junction-to-board and a junction-to-case thermal resistance. The junction-to-case
covers the situation where a heat sink is used or where a substantial amount of heat is dissipated from the
top of the package. The junction-to-board thermal resistance describes the thermal performance when most
of the heat is conducted to the printed-circuit board. It has been observed that the thermal performance of
most plastic packages and especially PBGA packages is strongly dependent on the board temperature; see
Figure
Freescale Semiconductor
θJC
is device-related and cannot be influenced by the user. The user adjusts the thermal environment to
4.
R
R
R
θJA
θJC
θCA
Estimation with Junction-to-Case Thermal Resistance
Estimation with Junction-to-Board Thermal Resistance
= junction-to-case thermal resistance (ºC/W)
= junction-to-ambient thermal resistance (ºC/W)
= case-to-ambient thermal resistance (ºC/W)
R
θJA
= R
Figure 4. Effect of Board Temperature Rise on Thermal Behavior
θJC
MPC885/MPC880 PowerQUICC Hardware Specifications, Rev. 7
+ R
θCA
θCA
. For instance, the user can change the airflow around
Thermal Calculation and Measurement
13