IDT79R465080MS View Datasheet(PDF) - Integrated Device Technology

Part Name

Description

Manufacturer

IDT79R465080MS

EMBEDDED 64-BIT ORION™ RISC MICROPROCESSOR

Integrated Device Technology 

IDT79R4650

COMMERCIAL TEMPERATURE RANGE

Thermal Considerations

The R4650 utilizes special packaging techniques to

improve the thermal properties of high-speed processors.

The R4650 is packaged using cavity down packaging in a

208-pin MQUAD.

The R4650 utilizes the MQUAD package (the “MS”

package), which is an all-aluminum package with the die

attached to a normal copper lead frame mounted to the

aluminum casing. Due to the heat-spreading effect of the

aluminum, the MQUAD package allows for an efficient

thermal transfer between the die and the case. The

aluminum offers less internal resistance from one end of

the package to the other, reducing the temperature

gradient across the package and therefore presenting a

greater area for convection and conduction to the PCB for

a given temperature. Even nominal amounts of airflow will

dramatically reduce the junction temperature of the die,

resulting in cooler operation.

The R4650 is guaranteed in a case temperature range of

0° to +85° C. The type of package, speed (power) of the

device, and airflow conditions affect the equivalent ambient

temperature conditions that will meet this specification.

The equivalent allowable ambient temperature, TA, can

be calculated using the thermal resistance from case to

ambient (∅CA) of the given package. The following

equation relates ambient and case temperatures:

DATA SHEET REVISION HISTORY

Changes to version dated September 1995:

AC Electrical Characteristics:

- In System Interface Parameters tables (R4650 and

RV4650), Data Setup and Data Hold minimums

changed.

TA = TC - P * ∅CA

where P is the maximum power consumption at hot

temperature, calculated by using the maximum ICC specifi-

cation for the device.

Typical values for ∅CA at various airflows are shown in

Table 6.

Preliminary

∅CA

Airflow (ft/min) 0 200 400 600 800 1000

208 MQUAD

21 13 10 9

8

7

Table 6: Thermal Resistance (∅CA) at Various Airflows

Note that the R4650 implements advanced power

management to substantially reduce the average power

dissipation of the device. This operation is described in the

IDT79R4640 and IDT79R4650 RISC Processor Hardware

User’s Manual.

5.8

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