TC642B MICROCHIP [Microchip Technology], TC642B Datasheet - Page 16

• Manufacturer Part Number: TC642B
• Manufacturer: MICROCHIP [Microchip Technology]

TC642B/TC647B
FIGURE 4-9:
DS21756B-page 16
V
Fire Start-up
MIN
FAULT = 1
Fan Pulse
Detected?
Power-Up
Operation
Power-on
Yes
No
Normal
Reset
(1 sec)
No
Timer
< V
SHDN
FAULT = Low,
V
V
Yes
MIN
?
Detected?
16 Pulses
Operation
Fan Fault
OUT
Normal
<V
No
Yes
= High
SHDN
Yes
No
TC642B/TC647B Behavioral Algorithm.
Shutdown
Fire Start-up
V
?
Detected?
Fan Pulse
Fan Fault
OUT
No
(1 sec)
Timer
= 0
Yes
No
V
V
MIN
MIN
Shutdown
Yes
V
OUT
> V
> V
= 0
REL
REL
?
?
No
Yes
Power-Up
Proportional to Greater
Yes
V
Pulse Detector
Clear Missing
of V
MIN
V
Operation
Fan Pulse
Detected?
IN
Normal
No
No
IN
V
No
< V
> V
OUT
or V
SHDN
OTF
MIN
?
Expired?
?
M.P.D.
Yes
No
Yes
FAULT = 0
(100 msec)
Diagnostic
Fan Pulse
Detected?
Yes
Timer
Fire
Yes
Yes
Shutdown
V
2003 Microchip Technology Inc.
TC642B Only
OUT
No
= 0
Fire Start-up
Detected?
Fan Pulse
Fan Fault
(1 sec)
Timer
V
MIN
Power-Up
No
> V
Yes
REL
?
No