Intel Pentium D 940 HH80553PG0884M User Manual

105

See the Support and Retention Module (SRM) External Design Requirements 

Document, Balanced Technology Extended (BTX) System Design Guide, and the Intel

information regarding the support and retention module and chassis interface and 

keepout zones. 

 illustrates the assembly stack including the SRM.

The boxed processor's Thermal Module Assembly (TMA) requires a +12 V power 

supply. The TMA will include power cable to power the integrated fan and will plug into 

the 4-wire fan header on the baseboard. The power cable connector and pinout are 

shown in 

. Baseboards must provide a compatible power header to support 

the boxed processor. 

contains specifications for the input and output signals at 

the TMA. 

The TMA outputs a SENSE signal, which is an open- collector output that pulses at a 

rate of 2 pulses per fan revolution. A baseboard pull-up resistor provides VOH to match 

the system board-mounted fan speed monitor requirements, if applicable. Use of the 

SENSE signal is optional. If the SENSE signal is not used, pin 3 of the connector should 

be tied to GND.

The TMA receives a Pulse Width Modulation (PWM) signal from the motherboard from 

the 4

th

 pin of the connector labeled as CONTROL.

T he rm a l  M od u le  A ssem bly

• H ea tsin k  &   Fan
• C lip
• S tructural  D uct

M othe rboard

S R M

C ha ssis  P an