XPC8260ZUIFBC Datasheet, PDF (12/50 Pages) Freescale Semiconductor, Inc – PowerQUICC II Integrated Communications Processor Hardware Specifications

Electrical and Thermal Characteristics
2 _{The leakage current is measured for nominal VDD, VCCSYN, and VDD.}
3 _{MPC8265 and MPC8266 only.}
2.2 Thermal Characteristics
Table 4 describes thermal characteristics.
Table 4. Thermal Characteristics for 480 TBGA Package
Characteristics
Symbol
Value
Unit
Air Flow
Junction to ambient
13¹
NC²
θ_JA
10¹
°C/W
1 m/s
11³
NC
8³
1 m/s
Junction to board⁴
θ_JB
4
°C/W
—
Junction to case⁵
θ_JC
1.1
°C/W
—
1 _{Assumes a single layer board with no thermal vias}
2 _{Natural convection}
3 _{Assumes a four layer board}
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).
2.3 Power Considerations
The average chip-junction temperature, T_J, in °C can be obtained from the following:
T_J = T_A + (P_D x θ_JA)
(1)
where
T_A = ambient temperature °C
θ_JA = package thermal resistance, junction to ambient, °C/W
P_D = P_INT + P_I/O
P_INT = I_DD x V_DD Watts (chip internal power)
P_I/O = power dissipation on input and output pins (determined by user)
For most applications P_I/O < 0.3 x P_INT. If P_I/O is neglected, an approximate relationship between P_D and
T_J is the following:
P_D = K/(T_J + 273° C)
(2)
Solving equations (1) and (2) for K gives:
K = P_D x (T_A + 273° C) + θ_JA x P_D2
(3)
MPC8260A PowerQUICC™ II Integrated Communications Processor Hardware Specifications, Rev. 2.0
12
Freescale Semiconductor