 2002-2012 Microchip Technology Inc.

DS21452C-page 7

TC652/TC653

TABLE 3-3:

TEMPERATURE SELECTION

GUIDE

Note: The Bold Type temperature settings are available for ordering.

Contact factory for other temperature selections.

anywhere from 25°C to 35°C.

As an example, suppose you wanted the fan to run at

40% speed at 25°C or less and go to full speed at

45°C. You would order the part number TC652AEVUA.

As another example, suppose you wanted the fan to

turn on at 30°C and go to full speed at 45°C. You

would order the part number TC653BEVUA.

4.0

TYPICAL APPLICATIONS

4.1

Reducing Switching Noise

For fans consuming more than 300mA, a slowdown

switching PWM induced noise (see Figure 4-1). The

value of this capacitor should be 4.7

F to 47F,

depending on the fan current consumption.

See Application Note AN771 “Suppressing Acoustic

Noise in PWM Fan Speed Control Systems” for more

information.

FIGURE 4-1:

REDUCING SWITCHING

NOISE

Temp.

Range °C

Part #

10°C

25

35

AC

30

40

BD

35

45

CE

15°C

25

40

AD

30

45

BE

20°C

25

45

AE

30

50

BF

35

55

CG

30°C

25

55

AG

1

8

2

7

3

6

4

5

PWM

GND

NC

GND

GND

0.01µF

10µF

2

Ω

1k

Ω

+12V

TC652

TC653

SHDN

FAULT

GND

µController

DC Fan

400mA

Max.

SHDN Control

Fan Fault Alert

Over-Temp

Alert

-