L6714 STMicroelectronics, L6714 Datasheet - Page 60

• Manufacturer Part Number: L6714
• Description: IC CTRLR 4PH W/DRIVERS 64-TQFP
• Manufacturer: STMicroelectronics

Specifications of L6714

• Applications: Controller, Intel VR10, VR11, AMD CPU
• Voltage - Input: 12V
• Number Of Outputs: 4
• Voltage - Output: 0.3 ~ 1.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP Exposed Pad, 64-eTQFP, 64-HTQFP, 64-VQFP
• Mounting Style: SMD/SMT
• Case: QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Thermal monitor
22
60/70
Thermal monitor
L6714 continuously senses the system temperature through TM pin: depending on the
voltage sensed by this pin, the device sets free the VR_FAN pin as a warning and, after
further temperature increase, also the VR_HOT pin as an alarm condition.
These signals can be used to give a boost to the system fan (VR_FAN) and improve the VR
cooling, or to initiate the CPU low power state (VR_HOT) in order to reduce the current
demand from the processor so reducing also the VR temperature. In a different manner,
VR_FAN can be used to initiate the CPU low power state so reducing the processor current
requirements and VR_HOT to reset the system in case of further dangerous temperature
increase.
Thermal sensors is external to the PWM control IC since the controller is normally not
located near the heat generating components: it is basically composed by a NTC resistor
and a proper biasing resistor R
system hot-spot in order to be sure to control the hottest point of the VR.
Typical connection is reported in
programmed by modifying the divider values in order to cross the VR_FAN and VR_HOT
thresholds at the desired temperatures.
Both VR_HOT and VR_FAN are active high and open drain outputs. Thermal Monitoring
Output are enabled if Vcc > UVLO
Figure 25. System thermal monitor typical connections.
4.00
3.80
3.60
3.40
3.20
3.00
2.80
2.60
2.40
2.20
2.00
80
85
TM Voltage - NTC=3300/4250K
TM
TM
90
Figure 25
. NTC must be connected as close as possible at the
VCC
(Place remotely, near Hot Spot)
.
Temperature [degC]
95
Sense Element
that also shows how the trip point can be easily
R
TM
100
105
+5V
Rtm = 330
Rtm = 390
Rtm = 470
110
115
120
L6714