TC648B Microchip Technology Inc., TC648B Datasheet - Page 26

• Manufacturer Part Number: TC648B
• Description: Pwm Fan Speed Controllers With Auto-shutdown, Fan Restart And Fansense Technology For Fault Detection
• Manufacturer: Microchip Technology Inc.

TC646B/TC648B/TC649B
FIGURE 5-13:
Bypass capacitor C
decouple the bias voltage. This is good to have, espe-
cially when using a MOSFET as the drive device. This
helps to give a localized low-impedance source for the
current required to charge the gate capacitance of Q
Two other bypass capacitors (labeled as C
added to decouple the V
added simply to remove any noise present that might
cause false triggerings or PWM jitter. R
resistor for the FAULT output. The value for this resistor
is system-dependent.
DS21755B-page 26
45.3k
237 k
R
R
2
1
+5V
17.8 k
R
4
VDD
+5V
Design Example Schematic.
IN
R
32.4 k
3
is added to the design to
and V
C
0.01 µF
0.01 µF
C
1.0 µF
C
B
Thermometrics
100 k @25°C
NHQ104B425R5
AS
B
F
nodes. These were
3
2
1
V
C
V
5
IN
AS
F
is the pull-up
B
) were also
®
TC649B
V
GND
8
1
DD
.
4
+
1.0 µF
SENSE
C
FAULT
VDD
V
OUT
6
7
5
R
10 k
5
C
0.1 µF
SENSE
R
2003 Microchip Technology Inc.
3.0
SENSE
+12V
Fan
Q
SI2302
or
MGSF1N02E
Panasonic
12V, 140 mA
FBA06T12H
1
®