SPC5123YVY400B Freescale Semiconductor, SPC5123YVY400B Datasheet - Page 23

• Manufacturer Part Number: SPC5123YVY400B
• Manufacturer: Freescale Semiconductor

Specifications of SPC5123YVY400B

• Lead Free Status / Rohs Status: Compliant

3.1.6
3.1.6.1
An estimation of the chip-junction temperature, T
where:
The junction to ambient thermal resistance is an industry standard value, which provides a quick and easy estimation of thermal
performance. Unfortunately, there are two values in common usage: the value determined on a single layer board, and the value
obtained on a board with two planes. For packages such as the PBGA, these values can be different by a factor of two. Which
value is correct depends on the power dissipated by other components on the board. The value obtained on a single layer board
is appropriate for the tightly packed printed circuit board. The value obtained on the board with the internal planes is usually
appropriate if the board has low power dissipation and the components are well separated.
Historically, the thermal resistance has frequently been expressed as the sum of a junction to case thermal resistance and a case
to ambient thermal resistance:
Freescale Semiconductor
T
R
P
A
D
θJA
1
2
3
4
5
6
Junction to Ambient Natural
Convection
Junction to Ambient Natural
Convection
Junction to Ambient (@200
ft/min)
Junction to Ambient (@200
ft/min)
Junction to Board
Junction to Case
Junction to Package Top
= ambient temperature for the package (ºC)
= power dissipation in package (W)
Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance,
mounting site (board) temperature, ambient temperature, air flow, power dissipation of other
components on the board, and board thermal resistance.
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 measured on the top surface of the board near the package.
Thermal resistance between the die and the case top surface as measured by the cold plate method
(MIL SPEC-883 Method 1012.1).
Thermal characterization parameter indicating the temperature difference between package top and
the junction temperature per JEDEC JESD51-2. When Greek letters are not available, the thermal
characterization parameter is written as Psi-JT.
Thermal Characteristics
= junction to ambient thermal resistance (ºC/W)
Heat Dissipation
1,3
1,3
Rating
1,2
1,3
5
4
6
Single layer board (1s)
Four layer board (2s2p)
Single layer board (1s)
Four layer board (2s2p)
Natural Convection
MPC5121E/MPC5123 Data Sheet, Rev. 3
Table 10. Thermal Resistance Data
T
J
Board Layers
J
, can be obtained from the following equation:
= T
A
—
—
+(R
θ
JA
×
P
D
)
R
R
R
Sym
R
R
R
Ψ
θJMA
θJMA
θJMA
θJC
θJA
θJB
JT
Value
Electrical and Thermal Characteristics
30
22
24
19
14
8
2
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
Unit
SpecID
D6.1
D6.2
D6.3
D6.4
D6.5
D6.6
D6.7
Eqn. 3
23