16
TSPC750A/740A
2128A–HIREL–01/02
Notes:
1. Thetemperatureisthejunctiontemperatureofthedie.Thethermalassistunit’srawoutputdoesnotindicateanabsolute
temperature,butitmustbeinterpretedbysoftwaretoderivetheabsolutejunctiontemperature.Forinformationaboutthe
useandcalibrationoftheTAU,seetheMotorolaapplicationnoteAN1800/D“programmingthethermalAssistUnitinthe
MPC750AMicroprocessor.Thisspecificationreflectsthetemperaturespansupportedbydesign.
2. ThecomparatorsettlingtimevaluemustbeconvertedintothenumberofCPUclocksthatneedtobewrittenintothe
THRM3SPR.
3. Guaranteedbydesignandcharacterization.
ThermalManagement
Information
Thissectionprovidesthermalmanagementinformationfortheceramicballgridarray
(CBGA)packageforair-cooledapplications.Properthermalcontroldesignisprimarily
dependentuponthesystem-leveldesigntheheatsink,airflowandthermalinterface
material.Toreducethedie-junctiontemperature,heatsinksmaybeattachedtothe
packagebyseveralmethods-adhesive,springcliptoholesintheprintedcircuitboardor
package,andmountingclipandscrewassembly;seeFigure7.Thisspringforceshould
notexceed5.5poundsofforce.
Figure7.
PackageExplodedCross-SectionalViewwithSeveralHeatSinkOptions
Ultimately,thefinalselectionofanappropriateheatsinkdependsonmanyfactors,such
asthermalperformanceatagivenairvelocity,spatialvolume,mass,attachment
method,assembly,andcost.
Table6.
ThermalSensorSpecifications
V
DD
=AV
DD
=L2AV
DD
=2.6V
DC
±
100mV,OV
DD
=L2OV
DD
=3.3±5%V
DC
,GND=0V
DC
,0
≤
T
j
<+125
°
C
Num
Characteristic
Min
Max
Unit
Notes
1
TemperatureRange
0
127
°
C
1
2
ComparatorSettlingTime
20
-
μs
2
3
Resolution
4
-
°
C
3
Adhesive
or
Thermal Interface Material
Heat Sink
CBGA Package
Heat Sink
Clip
Printed ± Circuit Board
Option