MAX6639ATE+ Maxim Integrated Products, MAX6639ATE+ Datasheet - Page 20

• Manufacturer Part Number: MAX6639ATE+
• Description: IC TEMP MONITOR 2CH 16-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX6639ATE+

• Function: Fan Control, Temp Monitor
• Topology: ADC, PWM Generator, Tach Counter
• Sensor Type: External & Internal
• Sensing Temperature: 0°C ~ 150°C, External Sensor
• Output Type: I²C™/SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2-Channel Temperature Monitor with Dual,
Automatic, PWM Fan-Speed Controller
3) Route the DXP and DXN traces parallel and close to
4) Connect guard traces to GND on either side of the
5) Route as few vias and crossunders as possible to
6) When introducing a thermocouple, make sure that
20
each other, away from any high-voltage traces such
as +12VDC. Avoid leakage currents from PCB cont-
amination. A 20MΩ leakage path from DXP ground
causes approximately +1°C error.
DXP/DXN traces. With guard traces, placing routing
near high-voltage traces is no longer an issue.
minimize copper/solder thermocouple effects.
both the DXP and the DXN paths have matching
thermocouples. In general, PCB-induced thermo-
______________________________________________________________________________________
CPU
TO CLOCK THROTTLE
GPU
TO SMBus
3.3V TO 5.5V
3.3V TO 5.5V
MASTER
SDA
SCL
ALERT
THERM
DXP1
DXN
DXP2
3.0V TO 3.6V
V
MAX6639
CC
GND
ADD
TACH1
7) Use wide traces. Narrow traces are more inductive
8) Placing an electrically clean copper ground plane
FANFAIL
5V
PWM1
PWM2
TACH2
OT
couples are not a serious problem. A copper solder
thermocouple exhibits 3µV/°C, and it takes approxi-
mately 200µV of voltage error at DXP/DXN to cause
a +1°C measurement error, so most parasitic ther-
mocouple errors are swamped out.
and tend to pick up radiated noise. The 10-mil widths
and spacings recommended are not absolutely nec-
essary (as they offer only a minor improvement in
leakage and noise), but use them where practical.
between the DXP/DXN traces and traces carrying
high-frequency noise signals helps reduce EMI.
5V
3.3V TO 5.5V
3.3V TO 5.5V
3.3V TO 5.5V
(5V OR 12V)
V
FAN
Typical Operating Circuit
TO SYSTEM SHUTDOWN
5V
(5V OR 12V)
V
FAN