Low Power, Programmable
Temperature Controller
a
TMP01*
FUNCTIO NAL BLO CK D IAGRAM
FEATURES
–55؇C to +125؇C (–67؇F to +257؇F) Operation
؎1.0؇C Accuracy Over Tem perature (typ)
Tem perature-Proportional Voltage Output
User Program m able Tem perature Trip Points
User Program m able Hysteresis
20 m A Open Collector Trip Point Outputs
TTL/ CMOS Com patible
Single-Supply Operation (4.5 V to 13.2 V)
Low Cost 8-Pin DIP and SO Packages
TEMPERATURE
SENSOR &
VOLTAGE
2.5V
SENSOR
VREF
1
2
V+
8
7
REFERENCE
R1
R2
R3
SET
HIGH
OVER
WINDOW
COMPARATOR
SET
LOW
3
4
6
5
UNDER
VPTAT
APPLICATIONS
GND
HYSTERESIS
GENERATOR
Over/ Under Tem perature Sensor and Alarm
Board Level Tem perature Sensing
Tem perature Controllers
Electronic Therm ostats
Therm al Protection
TMP01
HVAC System s
Industrial Process Control
Rem ote Sensors
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.
GENERAL D ESCRIP TIO N
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 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 µA (max).
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.
T he T MP01 is available in the low cost 8-pin epoxy mini-DIP
and SO (small outline) packages, and in die form.
*P r otected by U.S. P atent No. 5,195,827.
REV. C
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
© Analog Devices, Inc., 1995
One Technology Way, P.O. Box 9106, Norw ood. MA 02062-9106, U.S.A.
Tel: 617/ 329-4700
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