TC6502 Microchip Technology Inc., TC6502 Datasheet - Page 7

• Manufacturer Part Number: TC6502
• Description: Ultra Small Temperature Switches With Pin Selectable Hysteresis
• Manufacturer: Microchip Technology Inc.

5.0
The TC6501 and TC6503 have open-drain outputs and
are, therefore, intended to interface as microcontroller
reset inputs. Moreover, the combination of these two
devices can be used to implement a temperature
window alarm by wire-ORing the outputs and using an
external pull-up resistor (see Figure 5-1).
FIGURE 5-1:
Temperature Alarm.
The TC6502 can be used to control a DC fan. The fan
turns on when the sensed temperature rises above the
factory-set threshold and remains on until the
temperature falls below threshold minus the hysteresis
selected. An additional fail-safe measure could be
designed by using a second TC6502 with a higher
temperature threshold to alert the user of an impending
thermal shutdown, should the temperature continue to
rise (see Figure 5-2).
FIGURE 5-2:
Temperature Alert.
+5V
100 pF
2004 Microchip Technology Inc.
100 pF
100 pF
GND GND
GND GND
APPLICATIONS
TC6501
TC6501
+5V
+5V
+5V
V
V
CC
CC
R
T
T
HYST
HYST
OVER
OVER
HYST
HYST
PULL-UP
100 k
GND
GND
GND
V
V
V
GND
GND
GND
V
V
V
HYST
HYST
HYST
TC6502PO65
TC6502PO65
CC
CC
Over and Under
CC
CC
CC
CC
Fan Control with Over
TC6502PO45
TC6502PO45
GND GND
GND
GND
TC6502
TC6502
HYST
HYST
HYST
GND
GND
T
T
T
T
T
T
OVER
OVER
OVER
OVER
OVER
OVER
GND
GND
T
T
100 pF
UNDER
UNDER
TC6503
TC6503
GND
GND
Temperature
Fault
Fan Control
V
V
CC
CC
Out of Range
Temperature
HYST
HYST
The TC6504, with its push-pull output, may be used in
a similar fashion to turn on a heater element at cold
temperatures (see Figure 5-3).
FIGURE 5-3:
Thermostat.
Temperature
T
UNDER
100 pF
T
T
UNDER
UNDER
+ 2°C
GND
+5V
V
CC
TC6501/2/3/4
TC6504 As Heater
TC6504
GND HYST
T
Heater "On"
UNDER
DS21451D-page 7
Heater
12V
Time