TC664EUNTR Microchip Technology, TC664EUNTR Datasheet - Page 25

• Manufacturer Part Number: TC664EUNTR
• Description: IC PWM FAN SPEED CONTRLR 10-MSOP
• Manufacturer: Microchip Technology
• Type: Controller - SMBus Fan Speedr

Specifications of TC664EUNTR

• Applications: Fan Controller, Brushless (BLDC)
• Number Of Outputs: 1
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Product: Fan / Motor Controllers / Drivers
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 300 uA
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Voltage - Load: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

MOSFETs are very low, the TC664/TC665 devices can
charge and discharge them very quickly leading to very
fast edges. Of key concern is the turn-off edge of the
MOSFET. Since the fan motor winding is essentially an
inductor, when the MOSFET is turned off, the current
that was flowing through the motor wants to continue to
flow. If the fan does not have internal clamp diodes
around the windings of the motor, there is no path for
this current to flow through and the voltage at the drain
of the MOSFET may rise until the drain to source rating
of the MOSFET is exceeded. This will most likely cause
the MOSFET to go into avalanche mode. Since there is
FIGURE 7-7:
TABLE 7-2:
MMBT2222A
MPS2222A
MPS6602
SI2302
MGSF1N02E
SI4410
SI2308
Note 1: A series gate resistor may be used in order to control the MOSFET turn-on and turn-off times.
2002 Microchip Technology Inc.
Device
2: These drive devices are suggestions only. Fan currents listed are for individual fans.
FAN DRIVE DEVICE SELECTION TABLE (NOTE 2)
V
OUT
Package
Output Drive Device Configurations.
SOT-23
SOT-23
SOT-23
SOT-23
TO-92
TO-92
SO-8
R
BASE
a) Single Bipolar Transistor
Max Vbe sat /
Vgs(V)
1.2
1.2
1.2
2.5
2.5
4.5
4.5
GND
FAN
V
DD
R
Q
SENSE
1
Min hfe
NA
NA
NA
NA
50
50
50
very little energy in this occurrence, it will probably not
fail the device, but it would be a long term reliability
issue. The following is recommended:
• Ask how the fan is designed. If the fan has clamp
diodes internally, you will not experience this
problem. If the fan does not have internal clamp
diodes, it is a good idea to put one externally
(Figure 7-8). You can also put a resistor between
V
slow down the turn-off and limit this condition.
V
OUT
OUT
and the gate of the MOSFET, which will help
Vce/V
40
20
20
30
60
40
40
DS
b) N-Channel MOSFET
TC664/TC665
FAN
GND
V
Fan Current
DD
R
Q
(mA)
SENSE
1000
1
150
150
500
500
500
500
DS21737A-page 25
Rbase (ohms)
Suggested
Note 1
Note 1
Note 1
Note 1
800
800
301