TC647(2002) View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

TC647
(Rev.:2002)

PWM Fan Speed Controller with FanSense™ Technology

Microchip Technology 

TC647

Continuous restart mode is enabled by connecting the

FAULT output to VMIN through a 0.1 µF capacitor, as

shown in Figure 3-1. When so connected, the TC647

automatically attempts to restart the fan whenever a

fault condition occurs. When the FAULT output is

driven low, the VMIN input is momentarily pulled below

VSHDN, initiating a reset and clearing the fault

condition. Normal fan start-up is then attempted as pre-

viously described. The FAULT output may be

connected to external logic (or the interrupt input of a

microcontroller) to shut the TC647 down if multiple fault

pulses are detected at approximately one second

intervals.

From

System

Shutdown

Controller

+5V

10 kΩ

C1

0.01µF

From

Temp

Sensor

+5V

1

VIN

8

VDD

CB

1µF

6

FAULT

+5V

R1

Q2

(Optional)

R3

3

CB

0.01 µF 2

R4

CF

1 µF

VMIN

CF

TC647

VOUT 7

5

SENSE

GND

4

1 kΩ

TC647

RESET

1

0

Fault

Detected

+12V

Fan

Q1

RBASE

CSENSE

RSENSE

Note: The parallel combination of R3 and R4 must be >10 kΩ.

FIGURE 3-1:

Fan Fault Output Circuit.

DS21447C-page 6

 2002 Microchip Technology Inc.

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