Datasheet
Intel
®
82845G/82845GL/82845GV GMCH Datasheet 147
Electrical Characteristics
Electrical Characteristics 6
This chapter contains the thermal characteristics, power characteristics and DC characteristics for
the GMCH component.
Note: SDR signals are multiplexed with DDR signals. The specific signal’s timing and voltage level is
dependent on the 845G GMCH memory mode selected. This document differentiates the two by
following each signal with either SDR or DDR, as appropriate.
6.1 Absolute Maximum Ratings
Table 6-1 lists the GMCH’s maximum environmental stress ratings. Functional operation at the
absolute maximum and minimum is neither implied nor guaranteed. Functional operating
parameters are listed in the DC characteristics tables.
Warning: Stressing the device beyond the “Absolute Maximum Ratings” may cause permanent damage.
These are stress ratings only. Operating beyond the “operating conditions” is not recommended and
extended exposure beyond “operating conditions” may affect reliability.
6.2 Thermal Characteristics
The GMCH is designed for operation at die temperatures between 0 °C and 97 °C. The thermal
resistance of the package is given in Table 6-2. See the Intel
®
845G/845GL /845GV Chipset:
Intel
®
82845G/82845GL Graphics and Memory Controller Hub (GMCH) Thermal and
Mechanical Design Guidelines for more information.
NOTE: Refer to the Intel
®
845G/845GL/845GV Chipset: Intel
®
82845G/82845GL/82845GV Graphics and
Memory Controller Hub (GMCH) Thermal and Mechanical Design Guidelines
for more information.
Table 6-1. Absolute Maximum Ratings
Symbol Parameter Min Max Unit
T
die
Die Temperature under Bias 0 97 °C
T
storage
Storage Temperature -55 150 °C
VCC1_5 1.5 V Supply Voltage with respect to VSS -0.3 1.75 V
VTT AGTL+ buffer DC input voltage with respect to VSS -0.3 1.75 V
VCCSM(DDR) 2.5 V DDR Supply Voltage with respect to VSS -0.5 3 V
VCCSM(SDR) 3.3 V Supply Voltage with respect to VSS -0.3 3.6 V
Table 6-2. Intel
®
82845G GMCH Package Thermal Resistance
Parameter
Airflow Velocity in Meters/Second
No Air Flow 1 m/s
Ψ
jt
(°C/Watt)** (see note) (see note)
Θ
ja
(°C/Watt)** (see note) (see note)