TC655 Microchip Technology Inc., TC655 Datasheet - Page 8

• Manufacturer Part Number: TC655
• Description: Dual Smbus Pwm Fan Speed Controllers With Fan Fault Detection
• Manufacturer: Microchip Technology Inc.

TC654/TC655
3.0
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
3.1
A voltage range of 1.62 V to 2.6 V (typical) on this pin
drives an active duty-cycle of 30% to 100% on the
V
3.2
Positive terminal for the PWM ramp generator timing
capacitor. The recommended C
PWM operation.
3.3
Clocks data into and out of the TC654/TC655. See
Section 5.0 for more information on the serial interface.
3.4
Serial data is transferred on the SMBus in both direc-
tions using this pin. See Section 5.0 for more informa-
tion on the serial interface.
3.5
When the fan’s RPM falls below the user-set RPM
threshold (or OTF occurs with TC655), a logic low sig-
nal is asserted.
DS21734A-page 8
V
C
SCLK
SDA
GND
FAULT
SENSE2
SENSE1
V
V
OUT
IN
OUT
DD
F
Name
pin.
PIN FUNCTIONS
Analog Input (V
Analog Output (C
SMBus Serial Clock Input (SCLK)
Serial Data (Bi-directional) (SDA)
Digital (Open Drain) Output
(FAULT)
Analog Input
Analog Output
Serial Clock Input
Serial Data In/Out (Open Drain)
Ground
Digital (Open Drain) Output
Analog Input
Analog Input
Digital Output
Power Supply Input
PIN FUNCTION TABLE
IN
Function
)
F
)
F
is 1 µF for 30 Hz
3.6
Fan current pulses are detected at this pin. These
pulses are counted and used in the calculation of the
fan2 RPM.
3.7
Fan current pulses are detected at this pin. These
pulses are counted and used in the calculation of the
fan1 RPM.
3.8
This active high complimentary output drives the base
of an external transistor or the gate of a MOSFET.
3.9
The V
device. This bias supply voltage may be independent of
the fan power supply.
DD
Analog Input (SENSE2)
Analog Input (SENSE1)
Digital Output (V
Power Supply Input (V
pin with respect to GND provides power to the
2002 Microchip Technology Inc.
OUT
)
DD
)