Guidelines

Intel
®
7500 Chipset Thermal Mechanical Design Guide 15
Thermal Specifications
3 Thermal Specifications
3.1 Thermal Design Power (TDP)
Analysis indicates that real applications are unlikely to cause the IOH component to
consume maximum power dissipation for sustained time periods. Therefore, in order to
arrive at a more realistic power level for thermal design purposes, Intel characterizes
power consumption based on known platform benchmark applications. The resulting
power consumption is referred to as the Thermal Design Power (TDP). TDP is the target
power level to which the thermal solutions should be designed. TDP is not the
maximum power that the IOH can dissipate.
For TDP specifications, see Table 3-1 for the Intel 7500 chipset. FC-BGA packages have
poor heat transfer capability into the board and have minimal thermal capability
without thermal solution. Intel recommends that system designers plan for a heatsink
when using Intel 7500 chipset.
3.2 Case Temperature
To ensure proper operation and reliability of the Intel 7500 chipset, the case
temperature must be following to meet the thermal profile as specified in Table 3-1.
System and/or component level thermal solutions are required to maintain these
temperature specifications. Refer to Chapter 5 for guidelines on accurately measuring
package case temperatures.
Notes:
1. These specifications are based on preliminary post-silicon measurement. These are subject to change.
2. The idle power assumes the case temperature is at or below 95°C.
TSFSC = TSTHRHI – IOH Thermal sensor reading
Tcontrol = TSTHRHI – Threshold TSFSC
TSFSC: The “head-room” between the die temperature and the maximum allowable die
temperature is reported in degrees Centigrade through TSFSC. When TSFSC goes to
zero, it throttles.
Table 3-1. Intel® 7500 Chipset Thermal Design Power
Product TDP Idle Notes
Intel® 7500 chipset 27.1W 19.5W 1, 2
Table 3-2. Intel 7500 Chipset Thermal Specification and Tcontrol
Parameter Value
Tcase_max 95 °C
Tcase_min 5°C
Tcontrol 92 °C