TC649 Microchip, TC649 Datasheet - Page 8

• Manufacturer Part Number: TC649
• Description: PWM Fan Speed Controller
• Manufacturer: Microchip

TC649
FIGURE 4-1:
DS21449C-page 8
Hot Start
No
Auto-Shutdown
FAULT = 1,
V
V
IN
OUT
V
> V
FAULT = 1
V
IN
Fire Start-up
Power-Up
Fan Pulse
Detected?
Power-on
Yes
Operation
IN
Yes
No
No
Reset
(1 SEC)
= 0
Normal
< V
REL
Timer
< V
SHDN
?
AS
?
Yes
No
TC649 Behavioral Algorithm Flowchart.
No
Yes
Yes
V
V
IN
FAULT = 0,
Yes
IN
Fan Fault
V
Power-Up
> (V
OUT
< V
Shutdown
V
AS
Shutdown
Fire Start-up
V
OUT
Detected?
Fan Fault
Auto-
Fan Pulse
OUT
SHDN
(1 SEC)
+ V
No
= 0
Yes
Timer
HAS
YES
= 0
= 0
?
)?
(V
AS
V
+ V
No
IN
V
>
Yes
Yes
HAS
IN
> V
)
No
REL
?
Cycling
Power
No
Yes
No
Yes
V
Pulse Detector
Clear Missing
V
IN
Proportional
Detected?
No
Fan Pulse
Operation
No
IN
Normal
< V
to V
V
< V
OUT
SHDN
No
IN
AS
?
?
Expired?
M.P.D.
No
Yes
Yes
Diagnostic
(100msec)
Fan Pulse
Detected?
Shutdown
V
OUT
Timer
Auto
Fire
Yes
Yes
= 0
2002 Microchip Technology Inc.
(V
AS
No
Yes
V IN >
Shutdown
V
+ V
OUT
Yes
HAS
= 0
Detected?
Fan Pulse
Fan Fault
)
Fire Start-up
No
(1 Sec)
Timer
Hot Start
No
V
IN
Power-Up
> V
Yes
REL
No