TC620/TC621
5V, Dual Trip Point Temperature Sensors
Features
Package Type
• User Programmable Hysteresis and
Temperature Set Point
• Easily Programs with Two External Resistors
• Wide Temperature Detection Range:
- 0°C to 70°C: (TC620/TC621CCX)
- -40°C to +125°C: (TC620/TC621CVX)
- -40°C to +85°C: (TC620/TC621CEX)
• Onboard Temperature Sensing Applications
(TC620X)
• External NTC Thermistor for Remote Sensing
Applications (TC621X)
• Available in 8-Pin PDIP and SOIC Packages
8-PDIP
NC 1
LOW SET 2
HIGH SET 3
VDD
7 HIGH LIMIT
8
TC620XCPA
TC620XEPA
6 LOW LIMIT
5 CONTROL
GND 4
8-PDIP
THERMISTOR 1
HIGH SET 2
LOW SET 3
VDD
7 HIGH LIMIT
8
TC621XCPA
TC621XEPA
6 LOW LIMIT
5 CONTROL
GND 4
8-SOIC
Applications
•
•
•
•
Power Supply Over Temperature Detection
Consumer Equipment
Temperature Regulators
CPU Thermal Protection
NC 1
8
VDD
LOW SET 2
7
LOW LIMIT
5
CONTROL
HIGH SET 3
GND 4
TC620XCOA
TC620XEOA 6 HIGH LIMIT
TC620CVOA
8-SOIC
THERMISTOR 1
Device Selection Table
HIGH SET 2
Part Number
Package
Temperature
Range
TC620X*COA
8-Pin SOIC
0°C to +70°C
TC620X*CPA
8-Pin PDIP
0°C to +70°C
TC620X*EOA
8-Pin SOIC
-40°C to +85°C
TC620X*EPA
8-Pin PDIP
-40°C to +85°C
TC620C*VOA
8-Pin SOIC
-40°C to +125°C
TC621X*COA
8-Pin SOIC
0°C to +70°C
TC621X*CPA
8-Pin PDIP
0°C to +70°C
TC621X*EOA
8-Pin SOIC
-40°C to +85°C
TC621X*EPA
8-Pin PDIP
-40°C to +85°C
TC621C*VOA
8-Pin SOIC
-40°C to +125°C
Note:
*The part code will be C or H (see
Functional Block Diagrams).
VDD
HIGH
LIMIT
7
8
LOW SET 3
TC621XCOA
TC621XEOA 6 LOW LIMIT
GND 4
5 CONTROL
General Description
The TC620 and TC621 are programmable logic output
temperature detectors designed for use in thermal
management applications. The TC620 features an
onboard temperature 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 is programmed 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) output 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 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/TC621 are usable over operating
temperature ranges of 0°C to 70°C, -40°C to +125°C.
2001-2015 Microchip Technology Inc.
DS20001439E-page 1
TC620/TC621
Functional Block Diagrams
VDD
8
Temp. to
Voltage
Converter
4
TC620
+
2
LOW SET
VREF
GEN
7
LOW LIMIT
–
VREF
+
HIGH SET
3
VREF
GEN
6
HIGH LIMIT
–
R
S
Q
Q
5
CONTROL*
VDD
8
1
THERMISTOR
Thermistor
Interface
Circuit
4
TC621
+
HIGH SET
2
VREF
GEN
7
HIGH LIMIT
–
VREF
+
LOW SET
3
VREF
GEN
6
LOW LIMIT
–
R
S
Q
Q
5
CONTROL*
*Suffix code "C" denotes cooling option (High true CONTROL output).
Suffix code "H" denotes heating option (Low true CONTROL output).
DS20001439E-page 2
2001-2015 Microchip Technology Inc.
TC620/TC621
1.0
ELECTRICAL
CHARACTERISTICS
*Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. These are stress ratings only and functional
operation of the device at these or any other conditions
above those indicated in the operation sections of the
specifications is not implied. Exposure to Absolute
Maximum Rating conditions for extended periods may
affect device reliability.
Absolute Maximum Ratings*
Supply Voltage ....................................................... 20V
Input Voltage Any Input .. (GND – 0.3V) to (VDD +0.3V)
Package Power Dissipation (TA 70°C)
PDIP ............................................. 730 mW
SOIC ............................................. 470 mW
Derating Factors:
Plastic .......................................... 8 mW/°C
Operating Temperature:
V Version ......................... -40°C to +125°C
E Version ........................... -40°C to +85°C
C Version .............................. 0°C to +70°C
Storage Temperature ......................... -65°C to +150°C
TC620/TC621 ELECTRICAL SPECIFICATIONS
Electrical Characteristics: TA = 25°C, unless otherwise specified.
Symbol
Parameter
Min.
Typ.
Max.
Unit
Test Conditions
VDD
Supply Voltage Range
4.5
—
18
V
IDD
Supply Current
—
270
400
A
5V VDD 18V
ROUT
Output Resistance
—
400
1000
W
Output High or Low, 5V VDD 18V
IOUT
Output Current
—
—
1
mA
Temp. Sensed
Source/Sink
IOUT
Output Current
—
—
1
mA
Cool/Heat
Source/Sink
TERR
Absolute Accuracy
T-3
T
T+3
°C
T = Programmed Temperature
TEMPERATURE CHARACTERISTICS
Electrical Specifications: Unless otherwise noted, all parameters apply with 4.5V VDD 18V.
Parameters
Sym.
Min.
Typ.
Max.
Units
Specified Temperature Range (C)
TA
0
—
+70
°C
Specified Temperature Range (E)
TA
-40
—
+85
°C
Specified Temperature Range (V)
TA
-40
—
+125
°C
Conditions
Temperature Ranges
Maximum Junction Temperature
TJ
—
—
+150
°C
Storage Temperature Range
TA
-65
—
+150
°C
Thermal Resistance, 8L-PDIP
JA
—
125
—
°C/W
Thermal Resistance, 8L-SOIC
JA
—
155
—
°C/W
Package Thermal Resistances
2001-2015 Microchip Technology Inc.
DS20001439E-page 3
TC620/TC621
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
TC620 PIN FUNCTION TABLE
Pin No.
(8-Pin PDIP)
(8-Pin SOIC)
Symbol
1
NC
2
LOW SET
Low temperature set point. Connect an external 1% resistor from LOW SET to VDD
to set trip point.
3
HIGH SET
High temperature set point. Connect an external 1% resistor from HIGH SET to
VDD to set trip point.
4
GND
Description
No Internal Connection.
Ground Terminal.
5
CONTROL
Control output.
6
HIGH LIMIT
High temperature push/pull output.
7
LOW LIMIT
Low temperature push/pull output.
8
VDD
TABLE 2-2:
Power supply input.
TC621 PIN FUNCTION TABLE
Pin No.
(8-Pin PDIP)
(8-Pin SOIC)
Symbol
1
THERMISTOR
2
HIGH SET
High temperature set point. Connect an external 1% resistor from HIGH SET to
VDD to set trip point.
3
LOW SET
Low temperature set point. Connect an external 1% resistor from LOW SET to
VDD to set trip point.
4
GND
5
CONTROL
Control output.
6
LOW LIMIT
Low temperature push/pull output.
7
HIGH LIMIT
High temperature push/pull output.
8
VDD
DS20001439E-page 4
Description
Thermistor input.
Ground Terminal.
Power supply input.
2001-2015 Microchip Technology Inc.
TC620/TC621
DETAILED DESCRIPTION
The TC620 has a positive temperature coefficient temperature sensor and a dual threshold detector. Temperature set point programming is accomplished with
external resistors from the HIGH SET and LOW SET
inputs to VDD. The HIGH LIMIT and LOW LIMIT outputs
remain low as long as measured temperature is below
set point values. As measured temperature increases,
the LOW LIMIT output is driven high when temperature
equals the LOW SET set point (±3°C max). If temperature continues to climb, the HIGH LIMIT output is driven
high when temperature equals the HIGH SET set point
(Figure 3-1). The CONTROL (hysteresis) output is
latched in its active state at the temperature specified
by the HIGH SET resistor. CONTROL is maintained
active until temperature falls to the value specified by
the LOW SET resistor.
Care must also be taken to ensure the LOW SET
temperature setting is at least 5°C lower than the HIGH
SET temperature setting.
Figure 3-2 can help the user obtain an estimate of the
external resistor values required for the desired LOW
SET and HIGH SET trip points.
250
RESISTANCE, RTRIP (kΩ)
3.0
200
150
100
50
-55
-35
-15
5
25
45
65
85
105
125
TEMPERATURE (°C)
High Set Point
Temperature
FIGURE 3-2:
Trip Temperature.
TC620 Sense Resistors vs.
Low Set Point
Low Limit Output
3.2
High Limit Output
To prevent output “chattering” when measured
temperature is at (or near) the programmed trip point
values, the LOW SET and HIGH SET inputs each have
built-in hysteresis of -2°C below the programmed
settings (Figure 3-3).
Control Output (Cool Option
Control Output (Heat Option)
FIGURE 3-1:
Output Logic.
3.1
TC620/TC621 Input vs.
Built-in Hysteresis
Programming the TC620
The resistor values to achieve the desired trip point
temperatures on HIGH SET and LOW SET are
calculated using Equation 3-1:
EQUATION 3-1:
RTRIP = 0.5997 x T 2.1312
Set Point
(Set Point 2°C)
High Limit
or Low Limit
Output
Where:
RTRIP = Programming resistor in Ohms
T = The desired trip point temperature in degrees
Kelvin.
For example, a 50°C setting on either the HIGH SET
or LOW SET input is calculated using Equation 3-2 as
follows:
FIGURE 3-3:
Built-In Hysteresis on Low
Limit and High Limit Outputs.
As shown, the outputs remain in their active state
(hysteresis) until temperature falls an additional 2°C
below the user’s setting.
EQUATION 3-2:
RSET = 0.5997 x ((50 + 273.15)2.1312) = 133.6 k
Care must be taken to ensure the LOW SET programming resistor is a smaller value than the HIGH SET
programming resistor. Failure to do this will result in
erroneous operation of the CONTROL output.
2001-2015 Microchip Technology Inc.
DS20001439E-page 5
TC620/TC621
Using the TC621
The TC621 operation is similar to that of the TC620, but
requires an external NTC thermistor. Use the resistance 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.
350
300
THERMISTOR RESISTANCE (kΩ)
3.3
250
200
150
100
50
0
0
3.4
10
The TC621 uses an external thermistor to monitor the
controlling temperature. A thermistor with a resistance
value of approximately 100 k at 25°C is
recommended.
A temperature set point is selected by picking a resistor whose value is equal to the resistance of the thermistor at the desired temperature. For example, using
the data shown in Figure 3-4, a 30 k resistor between
HIGH TEMP (Pin 2) and VDD (Pin 8) sets the high
temperature trip point at +51°C and a 49 k resistor on
LOW TEMP (Pin 3) sets the low temperature trip point
to +41°C.
DS20001439E-page 6
20
30
40
50
60
70
TEMPERATURE (°C)
TC621 Thermistor Selection
FIGURE 3-4:
3.5
Typical NTC Thermistor.
TC620/TC621 Outputs
Both devices have complimentary output stages. They
are rated at a source or sink current of 1 mA maximum.
2001-2015 Microchip Technology Inc.
TC620/TC621
4.0
TYPICAL APPLICATIONS
4.1
Dual Speed Temperature Control
4.2
Temperature Controlled Fan
In the application in Figure 4-2, a high and a low temperature is selected by two RL and RH. The TC620
monitors the ambient temperature and turns the FET
switch on when the temperature exceeds the HIGH
TEMP set point. The fan remains on until the temperature decreases to the LOW TEMP set point. This
provides the hysteresis. In this application, the fan
turns on only when required.
In Figure 4-1, the Dual Speed Temperature Control
uses a TC620 and a TC4469 quad driver. Two of the
drivers of the TC4469 are configured in a simple oscillator. When the temperature is below the LOW TEMP
set point, the output of the driver is OFF. When the temperature exceeds the LOW TEMP set point, the
TC4469 gates the oscillator signal to the outputs of the
driver. This square wave signal modulates the remaining outputs and drives the motor at a low speed. If this
speed cannot keep the temperature below the HIGH
TEMP set point, then the driver turns on continuously
which increases the fan speed to high. The TC620 will
monitor the temperature and only allow the fan to operate when needed and at the required speed to maintain
the desired temperature. A higher power option can be
designed by adding a resistor and a power MOSFET.
The TC621 uses an external thermistor to monitor the
ambient temperature. This adds one part, but allows
more flexibility with the location of the temperature
sensor.
+12V
0.1 µF
2
3
High Temp. 1
5
50˚C
High 6 1N4148
Limit
TC620
Low 7
Limit
Temperature Scale
1M
1N4148
1 µF
Fan Motor
14
2
1
3
5
8
TC4469
4
0˚C – 30˚C (Fan Off)
30˚C – 50˚C (Fan Low)
50˚C – UP (Fan High)
FIGURE 4-1:
10 µF
8
Low Temp.
30˚C
VMOTOR
10k
13
4
6
9
10
11
12
100k
50 Ω
MOSFET
50 pF
Higher Power Option
7
Fan Motor
Dual Speed Temperature Control.
+12V
+12V
Thermistor
(NTC)
Low Temp. 1
RL
2
3
RH
4
High Temp.
FIGURE 4-2:
8
TC620
Fan Motor
7
6
5
MTP3055E
High
Temp.
1
RH
3
Low Temp. RL
4
2
8
TC621
Fan Motor
7
6
5
MTP3055E
Temperature Controlled Fan.
2001-2015 Microchip Technology Inc.
DS20001439E-page 7
TC620/TC621
4.5V to 18V
High
Temp.
Low
Temp.
1
2
3
4
TC620
8
7
6
5
1
2
3
4
5
6
7
TC4469
14
13
12
11
10
9
8
1k
1k
High
Temp.
Warning
Low
Temp.
Warning
Heating/Cooling
Equipment
FIGURE 4-3:
DS20001439E-page 8
Heating and Cooling Application.
2001-2015 Microchip Technology Inc.
TC620/TC621
5.0
PACKAGING INFORMATION
5.1
Package Marking Information
8-Lead PDIP (300 mil)
XXXXXXXX
XXXXXNNN
YYWW
Example
TC620C
CPA e^^3 256
1503
TC621C
CPA ^^
e3256
1503
8-Lead SOIC (150 mil)
Example
TC620HC
3 1503
OA e^^
NNN
256
TC621HE
OA e^^3 1503
256
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC® designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3 )
can be found on the outer packaging for this package.
In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
2001-2015 Microchip Technology Inc.
DS20001439E-page 9
TC620/TC621
!
;'
*"'#
'
<
$."+
"
"
'
<
&''
$'
''
:==...*
*=
<
N
NOTE 1
E1
1
3
2
D
E
A2
A
L
A1
c
e
eB
b1
b
>'"
*
"A*'"
?#*,
&"
?1@4
?
?
?B
C
F
'
'
'
G
G
$
$<
很抱歉,暂时无法提供与“TC621CEOA713”相匹配的价格&库存,您可以联系我们找货
免费人工找货