MPC8308CVMAGDA datasheet(80/88 Pages) FREESCALE

80 / 88 page

MPC8308 PowerQUICC II Pro Processor Hardware Specification, Rev. 1

Freescale Semiconductor

Thermal

22.2

Thermal Management Information

For the following sections, PD = (VDD × IDD) + PI/O, where PI/O is the power dissipation of the I/O drivers.

22.2.1

Estimation of Junction Temperature with Junction-to-Ambient

Thermal Resistance

An estimation of the chip junction temperature, TJ, can be obtained from the equation:

TJ = TA + (RθJA × PD)

where:

TJ = junction temperature (°C)

TA = ambient temperature for the package (°C)

RθJA = junction-to-ambient thermal resistance (°C/W)

PD = power dissipation in the package (W)

The junction-to-ambient thermal resistance is an industry standard value that provides a quick and easy

estimation of thermal performance. As a general statement, the value obtained on a single-layer board is

appropriate for a 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. Test cases have demonstrated that errors of a factor of two (in the quantity TJ – TA) are possible.

22.2.2

Estimation of Junction Temperature with Junction-to-Board

Thermal Resistance

The thermal performance of a device cannot be adequately predicted from the junction-to-ambient thermal

resistance. The thermal performance of any component is strongly dependent on the power dissipation of

surrounding components. In addition, the ambient temperature varies widely within the application. For

many natural convection and especially closed box applications, the board temperature at the perimeter

(edge) of the package is approximately the same as the local air temperature near the device. Specifying

Notes:

1. 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.

2. Per JEDEC JESD51-2 with the single layer board horizontal. Board meets JESD51-9 specification.

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

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).

6. 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.

Table 59. Package Thermal Characteristics for MAPBGA (continued)

Characteristic

Board Type

Symbol

Value

Unit

Notes

MPC8308CVMAGDA 데이터시트(PDF) 80 Page - Freescale Semiconductor, Inc

MPC8308CVMAGDA 데이터시트(HTML) 80 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88

데이터시트 다운로드

링크 URL