TC620HEPA Microchip Technology, TC620HEPA Datasheet - Page 6

• Manufacturer Part Number: TC620HEPA
• Description: IC TEMP SNSR 5V DUAL TRIP 8-DIP
• Manufacturer: Microchip Technology

Specifications of TC620HEPA

• Sensing Temperature: -40°C ~ 85°C
• Output Type: Active High
• Voltage - Supply: 4.5 V ~ 18 V
• Accuracy: ±1°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Temperature Threshold: Programmable
• Supply Voltage (max): 18 V
• Supply Voltage (min): 4.5 V
• Description/function: 5 V, Dual Trip Point Temperature Sensor
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Current: 400 uA
• Ic Output Type: Inverted
• Sensing Accuracy Range: ± 3°C
• Temperature Sensing Range: -40°C To +85°C
• Supply Voltage Range: 4.5V To 18V
• Sensor Case Style: DIP
• No. Of Pins: 8
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TC620/TC621
3.3
The TC621 operation is similar to that of the TC620, but
requires an external NTC thermistor. Use the resis-
tance versus temperature curve of the thermistor to
determine the values of the programming resistors.
Note that the pin numbers for the HIGH SET and LOW
SET programming resistors for the TC621 are reversed
versus that of the TC620 (i.e., the resistor value on
HIGH SET [Pin 2] should always be lower than the one
connected to LOW SET [Pin 3]). Also note that the
outputs of the TC621 are LOW TRUE when used with
an NTC thermistor.
3.4
The TC621 uses an external thermistor to monitor the
controlling temperature. A thermistor with a resistance
value
recommended.
tor whose value is equal to the resistance of the ther-
mistor at the desired temperature. For example, using
the data shown in Figure 3-4, a 30kΩ resistor between
HIGH TEMP (Pin 2) and V
temperature trip point at +51°C and a 49kΩ resistor on
LOW TEMP (Pin 3) sets the low temperature trip point
to +41°C.
DS21439B-page 6
A temperature set point is selected by picking a resis-
of
Using the TC621
TC621 Thermistor Selection
approximately
DD
100kΩ
(Pin 8) sets the high
at
25°C
is
FIGURE 3-4:
3.5
Both devices have complimentary output stages. They
are rated at a source or sink current of 1mA maximum.
150
350
300
250
200
100
50
0
0
TC620/TC621 Outputs
10
20
TEMPERATURE (˚C)
THERMISTOR
TYPICAL NTC
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2002 Microchip Technology Inc.
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50
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