TELCOM TC07

1
TC07
3V LOGIC OUTPUT TEMPERATURE SENSOR WITH
PROGRAMMABLE HYSTERESIS
2
FEATURES
GENERAL DESCRIPTION
■
The TC07 is a programmable, logic output temperature
detector that operates from power supply levels as low as
2.7V. Programming is accomplished with external resistors
connected from the temperature setpoint input (TSET) and
the hysteresis control input (HSET) to VDD.
Complimentary outputs (OUT and OUT) are driven
active when temperature exceeds the temperature threshold programmed by the resistor on TSET. The states of these
outputs are maintained (latched) until temperature falls
below threshold programmed by the resistor on HSET.
The TC07 is useful over a maximum temperature range
of – 40°C to +125°C (TC07VxA). It features low (<130µA)
supply current and small physical size 8-pin MSOP and
8-pin SOIC packages, making it suitable for a wide variety
of applications.
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■
■
■
User Programmable Hysteresis and Temperature
Set Point
Easily Programs with Two External Resistors
Wide Temperature Detection Range
TC07CxA ....................................... 0°C to +70°C
TC07ExA ................................ – 40°C to +85°C
TC07VxA ............................... – 40°C to +125°C
Small 8-Pin MSOP and 8-Pin SOIC Packages
Cost Effective
APPLICATIONS
■
■
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Power Supply Over-Temperature Detection
Consumer Equipment
Temperature Regulators
Computer Equipment
Package
TC07COA
TC07CUA
TC07EOA
TC07EUA
TC07VOA
TC07VUA
8-Pin SOIC
8-Pin MSOP
8-Pin SOIC
8-Pin MSOP
8-Pin SOIC
8-Pin MSOP
8-Pin SOIC
Temp. Range
0°C to +70°C
0°C to +70°C
– 40°C to +85°C
– 40°C to +85°C
– 40°C to +125°C
– 40°C to +125°C
NC
1
8
VDD
HSET
2
7
NC
TSET
3
6
OUT
GND
4
5
OUT
TC07COA
TC07EOA
TC07VOA
5
8-Pin MSOP
6
FUNCTIONAL BLOCK DIAGRAM
TEMP
SENSOR
+
4
PIN CONFIGURATION
ORDERING INFORMATION
Part No.
3
S
Q
NC
1
HSET
TSET
3
GND
4
8
2
TC07CUA
TC07EUA
TC07VUA
VDD
7
NC
6
OUT
5
OUT
OUT
TEMPERATURE
TO VOLTAGE
CONVERTER
–
7
–
OUT
+
R
Q
VOLTAGE
REFERENCE
GENERATOR
TSET
HSET
VDD
8
GND
TC07-1 9/18/96
TELCOM SEMICONDUCTOR, INC.
2-11
3V LOGIC OUTPUT TEMPERATURE
SENSOR WITH PROGRAMMABLE
HYSTERESIS
TC07
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage ..............................................................7V
Input Voltage Any Input ...... (GND – 0.3V) to (VDD + 0.3V)
Operating Temperature ......................... – 40°C to +125°C
Maximum Chip Temperature ................................. +150°C
Storage Temperature ............................ – 65°C to +150°C
Lead Temperature (Soldering, 10 sec) ................. +300°C
* 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.
ELECTRICAL CHARACTERISTICS: TA = Over Operational Temperature Range, unless otherwise specified.
Symbol
Parameter
Conditions
VDD
IDD
VOH
VOL
H
TSET
HSET
Supply Voltage Range
Supply Current
Output Voltage (High)
Output Voltage (Low)
Minimum Hysteresis
Absolute Accuracy
Absolute Accuracy
2.7V < VCC < 5.5V
IOUT = 500µA
IOUT = 1mA
HSET < TSET
T = Programmed Temperature
T = Programmed Temperature
DETAILED DESCRIPTION
The TC07 programs with resistors connected from the
TSET and HSET inputs to VDD. Output pins OUT and OUT are
driven active when temperature exceeds the setting determined by the programming resistor on TSET. The outputs are
maintained (latched) in their active states until temperature
drops below the setting determined by the programming
resistor on HSET (Figure 1).
TEMPERATURE
TEMPERATURE SET BY
RESISTOR ON TSET
HYSTERESIS SET BY
RESISTOR ON HSET
OUT
OUT
Figure 1. TC07 Output Waveforms
2-12
Min
Typ
Max
Unit
2.7
—
0.8 x VDD
—
–5
T–3
T–5
—
130
—
—
—
T±1
T±1
5.5
300
—
0.25 x VDD
—
T+3
T+5
V
µA
V
V
°C
°C
°C
APPLICATIONS
Trip Point Programming
The resistor values required to achieve the desired
trip-point temperatures on TSET and HSET are calculated
using the formula below:
RTRIP = 0.6 x T 2.13
Where:
RTRIP
T
= Programming resistor value in Ohms
= Desired trip point temperature in degrees
Kelvin.
For example, to program the TC07 outputs to go active
at 50°C and inactive at 30°C, the TSET and HSET programming resistors are calculated as follows:
TSET = 0.6 x ((50 + 273.15)2.13) = 132.8kΩ
HSET = 0.6 x ((30 + 273.15)2.13) = 115.9kΩ
Resistance values for TSET and HSET can be approximated using Figure 2. Care must be taken to ensure the
HSET programming resistor is a smaller value than the TSET
programming resistor. The temperature programmed on
HSET must be at least 5°C lower than the temperature value
programmed by TSET. That is: HSET ≤ TSET – 5°C.
TELCOM SEMICONDUCTOR, INC.
3V LOGIC OUTPUT TEMPERATURE
SENSOR WITH PROGRAMMABLE
HYSTERESIS
1
TC07
Cooling and Heating Applications
RESISTANCE (kΩ)
250
The TC07 can be used to control a DC fan as shown in
Figure 3. The fan turns on when the sensed temperature
rises above TSET and remains on until the temperature falls
below HSET. The amount of "over-cooling" performed by the
fan is dependent on the programmed hysteresis.
Figure 4 shows the TC07 acting as a heater thermostat.
Circuit operation is identical to that of the cooling fan
application.
200
150
100
50
-55
-35
-15
5
25
45
65
85
105
125
TEMPERATURE (°C)
2
3
Figure 2. Programming Resistor Values vs. Temperature
+2.7 to 5.5V
+2.7 to 5.5V
RT
4
+12V
+12V
RH
RH
NC
VDD
HSET
NC
VDD
NC
+
HEATER
DC FAN
NC
HSET
RT
TC07
TC07
TSET
OUT
GND
OUT
LOGIC
LEVEL
MOSFET
TSET
OUT
GND
OUT
LOGIC
LEVEL
MOSFET
5
TEMPERATURE
TEMPERATURE
6
TSET
HSET
OUT
TSET
HSET
7
OUT
FAN "ON"
Figure 3. TC07 as a Fan Controller
TELCOM SEMICONDUCTOR, INC.
HEATER "ON"
8
Figure 4. TC07 as a Heater Thermostat
2-13