Balanced Technology Extended (BTX) Boxed Processor Specifications
Document, Balanced Technology Extended (BTX) System Design Guide, and the
appropriate processor Thermal and Mechanical Design Guidelines (see Section 1.2) for
more detailed information regarding the support and retention module and chassis
interface and keepout zones. Figure 29 illustrates the assembly stack including the
SRM.
Figure 29.
Assembly Stack Including the Support and Retention Module
Thermal Module Assembly
• Heatsink & Fan
• Clip
• Structural Duct
Motherboard
SRM
Chassis Pan
8.2
Electrical Requirements
8.2.1
Thermal Module Assembly Power Supply
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 Figure 30. Baseboards must provide a compatible power header to support
the boxed processor. Table 36 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 4th pin of the connector labeled as CONTROL.
Datasheet
99