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TC620
TC621
5V, DUAL TRIP POINT TEMPERATURE SENSORS
FEATURES
s
s
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User-Programmable Hysteresis and Temperature
Set Point
Easily Programs with 2 External Resistors
Wide Temperature Detection
Range ................ 鈥?40
擄
C to +125
擄
C (TC620/621CVx)
External Thermistor for Remote Sensing
Applications (TC621x)
GENERAL DESCRIPTION
The TC620 and TC621 are programmable logic output
temperature detectors designed for use in thermal manage-
ment applications. The TC620 features an on-board tem-
perature sensor, while the TC621 connects to an external
NTC thermistor for remote sensing applications.
Both devices feature dual thermal interrupt outputs
(HIGH LIMIT and LOW LIMIT), each of which program with
a single external resistor. On the TC620, these outputs are
driven active (high) when measured temperature equals the
user-programmed limits. The CONTROL (hysteresis) out-
put is driven high when temperature equals the high limit
setting, and returns low when temperature falls below the
low limit setting. This output can be used to provide simple
ON/OFF control to a cooling fan or heater. The TC621
provides the same output functions except that the logical
states are inverted.
The TC620/621 are usable over a maximum tempera-
ture range of 鈥?40擄C to +125擄C.
Ambient
Temperature
鈥?40擄C to +85擄C
鈥?40擄C to +85擄C
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APPLICATIONS
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Power Supply Overtemperature Detection
Consumer Equipment
Temperature Regulators
CPU Thermal Protection
ORDERING INFORMATION
Part No.
TC620x*COA
TC620x*CPA
TC620x*EOA
TC620x*EPA
TC620CVOA
TC621x*COA
TC621x*CPA
Package
Ambient
Temperature
8-Pin SOIC
0擄C to +70擄C
8-Pin Plastic DIP
0擄C to +70擄C
8-Pin SOIC
鈥?40擄C to +85擄C
8-Pin Plastic DIP 鈥?40擄C to +85擄C
8-Pin SOIC
鈥?40擄C to +125擄C
8-Pin SOIC
0擄C to +70擄C
8-Pin Plastic DIP
0擄C to +70擄C
Part No.
TC621x*EOA
TC621x*EPA
Package
8-Pin SOIC
8-Pin Plastic DIP
*The part code will be C or H (see Functional Block Diagram, below,
and page 2).
FUNCTIONAL BLOCK DIAGRAM
V
DD
8
Temp
to
Voltage
Converter
1
Thermistor
Interface
Circuit
8
V
DD
TC620
4
THERMISTOR
TC621
4
+
2
LOW SET
V
REF
GEN
7
LOW LIMIT
HIGH SET
2
V
REF
GEN
+
鈥?/div>
7
HIGH LIMIT
鈥?/div>
V
REF
V
REF
+
HIGH SET
3
V
REF
GEN
6
HIGH LIMIT
LOW SET
R
Q
S
Q
5
CONTROL*
3
V
REF
GEN
+
鈥?/div>
R
Q
S
Q
6
LOW LIMIT
鈥?/div>
5
CONTROL*
*Suffix code "C" denotes cooling option (high true CONTROL output);
suffix code "H" denotes heating option (low true CONTROL output).
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TC620/1-9 11/4/96
TELCOM SEMICONDUCTOR, INC.
2-15
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