mpc8250 Freescale Semiconductor, Inc, mpc8250 Datasheet - Page 10

• Manufacturer Part Number: mpc8250
• Description: Mpc8250 Powerquicc Ii Integrated Communications Processor
• Manufacturer: Freescale Semiconductor, Inc

Electrical and Thermal Characteristics
2.2
Table 4
2.3
The average chip-junction temperature
where
For most applications P
T
Solving equations (1) and (2) for K gives:
10
J
is the following:
1
2
3
1
2
Junction to ambient—
single-layer board
Junction to ambient—
four-layer board
Junction to board
Junction to case
measured on the top surface of the board near the package.
Method 1012.1).
Thermal resistance between the die and the case top surface as measured by the cold plate method (MIL SPEC-883
Assumes no thermal vias
Thermal resistance between the die and the printed circuit board per JEDEC JESD51-8. Board temperature is
DC current, it is recommended to either pull unused pins to GND or VDDH, or to configure them as outputs.
The default configuration of the CPM pins (PA[0–31], PB[4–31], PC[0–31], PD[4–31]) is input. To prevent excessive
The leakage current is measured for nominal VDD, VCCSYN, and VDD.
T
T
θ
P
P
P
P
K = P
describes thermal characteristics.
Characteristic
A
INT
I/O
D
JA
J
D
Thermal Characteristics
Power Considerations
= T
= ambient temperature °C
= K/(T
= P
= package thermal resistance
= power dissipation on input and output pins (determined by user)
= I
D
A
INT
DD
x (T
+ (P
J
x V
+ 273° C)
+ P
A
3
D
2
1
+ 273° C) +
x
DD
I/O
θ
I/O
JA
Watts (chip internal power)
)
< 0.3 x P
Symbol
θ
θ
θ
θ
JA
JB
JC
JA
MPC8250 Hardware Specifications, Rev. 1
x P
INT
Table 4. Thermal Characteristics
,
junction to ambient
,
D
. If P
T
2
J
(ZU package)
,
480 TBGA
in °C can be obtained from the following:
I/O
1.1
13
10
11
8
4
is neglected
Value
(VR package)
,
°C/W
516 PBGA
,
an approximate relationship between P
24
18
16
13
8
6
°C/W
°C/W
°C/W
Unit
Freescale Semiconductor
Natural convection
Natural convection
Air Flow
1 m/s
1 m/s
—
—
(3)
(1)
(2)
D
and