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FUNCT IONAL BLOCK DIAGRAM
REV. C
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
LowPower, Programmable
Temperature Controller
TMP01*
Analog Devices, Inc., 1995
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
FEATURES
–55
8
C to +125
8
C (–67
8
F to +257
8
F) Operation
6
1.0
8
C Accuracy Over Temperature (typ)
Temperature-Proportional Voltage Output
User Programmable Temperature Trip Points
User Programmable Hysteresis
20 mA Open Collector Trip Point Outputs
TTL/CMOS Compatible
Single-Supply Operation (4.5 V to 13.2 V)
Low Cost 8-Pin DIP and SO Packages
APPLICATIONS
Over/Under Temperature Sensor and Alarm
Board Level Temperature Sensing
Temperature Controllers
Electronic Thermostats
Thermal Protection
HVAC Systems
Industrial Process Control
Remote Sensors
GE NE RAL DE SCRIPT ION
T he T MP01 is a temperature sensor which generates a voltage
output proportional to absolute temperature and a control signal
from one of two outputs when the device is either above or
below a specific temperature range. Both the high/low tempera-
ture trip points and hysteresis (overshoot) band are determined
by user-selected external resistors. For high volume production,
these resistors are available on-board.
T he T MP01 consists of a bandgap voltage reference combined
with a pair of matched comparators. T he reference provides
both a constant 2.5 V output and a voltage proportional to abso-
lute temperature (VPT AT ) which has a precise temperature co-
efficient of 5 mV/K and is 1.49 V (nominal) at +25
°
C. T he
comparators compare VPT AT with the externally set tempera-
ture trip points and generate an open-collector output signal
when one of their respective thresholds has been exceeded.
*
Protected by U.S. Patent No. 5,195,827.
Hysteresis is also programmed by the external resistor chain and
is determined by the total current drawn out of the 2.5 V refer-
ence. T his current is mirrored and used to generate a hysteresis
offset voltage of the appropriate polarity after a comparator has
been tripped. T he comparators are connected in parallel, which
guarantees that there is no hysteresis overlap and eliminates
erratic transitions between adjacent trip zones.
T he T MP01 utilizes proprietary thin-film resistors in conjunc-
tion with production laser trimming to maintain a temperature
accuracy of
±
1
°
C (typ) over the rated temperature range, with
excellent linearity. T he open-collector outputs are capable of
sinking 20 mA, enabling the T MP01 to drive control relays di-
rectly. Operating from a +5 V supply, quiescent current is only
500
μ
A (max).
T he T MP01 is available in the low cost 8-pin epoxy mini-DIP
and SO (small outline) packages, and in die form.
VPTAT
V+
TEMPERATURE
SENSOR &
VOLTAGE
REFERENCE
2.5V
SENSOR
1
2
3
4
8
7
6
5
HYSTERESIS
GENERATOR
WINDOW
COMPARATOR
R1
TMP01
VREF
SET
HIGH
SET
LOW
GND
R2
R3
UNDER
OVER