TK11052
APPLICATION HINTS (CONT.)
(9)
Rb =
VREF x TSH x TC
(0.4925 + TSET x TC - TSH x TC) x ISH
=
1183
181.07 -
x TSH
(TSET
-
TSH)
x
103
Example:
Ra and Rb when set temperature is 0 °C and temperature hysteresis is 5 °C.
Ra =
1183 x TSH
80.74 + (TSET - TSH)
x 103
= 78.096 x 103 ≈ 78.1 kΩ
Rb =
1183 x TSH
x 103
181.07 - (TSET - TSH)
= 31.789 x 103 ≈ 31.8 kΩ
Thermostat IC Application
Example:
• WINDOW TYPE OUTPUT
The following application protects the circuit within the operating temperature range of 0 to 85 °C. When the temperature
is 0 °C or less, or 85 °C or more, the N channel Mos transistor is turned OFF.
When the temperature returns to between 5 and 80 °C by the hysteresis function, the N channel Mos transistor is turned
ON.
VCC
OUT1 "H"
"L"
62 kΩ 36 kΩ
IN1
OUT1
300 kΩ
OUT2 "L"
"H"
31.8 kΩ 78.1 kΩ
IN2
OUT2
"H"
VCC
VCC
GND
Protected OUT1 + OUT2 "L"
Circuit
"L"
Vref
NC
0 10
80 90
Temperature (°C)
• TEMPERATURE FUSE
The following application is a temperature fuse circuit. The output of the TK11052M becomes a High Level when the
surrounding temperature exceeds 85 °C and the P channel Mos transistor is turned off. Even if the surrounding
temperature drops, the P channel Mos transistor remains off.
62 kΩ
VCC
0.1 µF
32 kΩ
IN1
IN2
VCC
Vref
OUT1
OUT2
GND
NC
VCC VCC
300 kΩ
Protected
Circuit
1.011 V
OUT1
"L"
"H"
OUT2 "L"
0 10
80 90
Temperature (°C)
July 1999 TOKO, Inc.
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