MAX6643LBBAEE+ Maxim Integrated Products, MAX6643LBBAEE+ Datasheet - Page 9

• Manufacturer Part Number: MAX6643LBBAEE+
• Description: IC CNTRLR FAN SPEED 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6643LBBAEE+

• Function: Fan Control, Temp Monitor
• Topology: ADC, PWM Generator, Tach Counter
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: PWM
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Full Temp Accuracy: +/- 3.5 C, +/- 3 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 3. MAX6644 Using Two External Transistors to Measure Remote Temperatures and Control Two 2-Wire Fans. The fan’s power-
supply current is monitored to detect failure of either fan. Connect pin 10 to pin 11 if only one fan is used.
Figure 4. MAX6645 Using Two External Transistors to Measure Remote Temperatures and Control Two 2-Wire Cooling Fans. The
fan’s power-supply current is monitored to detect failure of either fan. Connect FAN_IN1 to FAN_IN2 if only one fan is used.
Automatic PWM Fan-Speed Controllers with
TO FANFAIL
TO FANFAIL
ALARM
ALARM
4.7k
4.7k
_______________________________________________________________________________________
2
3
5
1
4
2
3
4
5
6
8
1
7
FANFAIL
TACHSET
DXP2
GND
DXP1
TH1
FANFAIL
DXP2
GND
DXP1
TL2
TL1
TACHSET
V
DD
V
DD
(+3.0V TO +5.5V)
MAX6645
(+3.0V TO +5.5V)
MAX6644
PWM_OUT
FAN_IN1
FAN_IN2
PWM_OUT
FAN_IN1
FAN_IN2
V
OT
DD
OT2
V
TH2
OT1
OT
DD
9
8
10
7
6
15
14
13
12
11
9
16
10
TACHOMETER MODE
TACHOMETER MODE
Overtemperature Output
4.7k
CURRENT-SENSE
MODE
CURRENT-SENSE
MODE
4.7k
TO OVERTEMPERATURE
ALARM
TO OVERTEMPERATURE
ALARM
4.7k
4.7k
0.1 F
0.1 F
+V
+V
FAN
FAN
(5V OR 12V)
(5V OR 12V)
N
2.0
N
N
2.0
+V
+V
FAN
FAN
(5V OR 12V)
(5V OR 12V)
9