Intel 80960HD - Manual (Page 31)

80960HA/HD/HT
Datasheet 31
3.3 Package Thermal Specifications
The 80960Hx is specified for operation when T
C
(case temperature) is within the range of
0 °C to 85 °C. T
C
may be measured in any environment to determine whether the 80960Hx is
within the specified operating range. Measure the case temperature at the center of the top surface,
opposite the pins. Refer to
Figure 5 .
T
A
(ambient temperature) is calculated from
θ
CA
(thermal resistance from case to ambient) using
Equation 1 :
Equation 1. Calculation of Ambient Temperature (T
A
)
Table 12 shows the maximum T
A
allowable (without exceeding T
C
) at various airflows and
operating frequencies (f
CLKIN
).
Note that T
A
is greatly improved by attaching fins or a heatsink to the package. P (maximum power
consumption) is calculated by using the typical I
CC
as tabulated in Section 4.6, “DC
Specifications” on page 40 and V
CC
of 3.3 V.
T
A
T
C
P
θ
CA
⋅ ( )
– =
Figure 5. Measuring 80960Hx PGA Case Temperature
Measure PGA/PQ4 temperature at
center of top surface