Analog Devices AD22105AR-REEL7, AD22105AR Datasheet
Low Voltage, Resistor Programmable
a
FEATURES
User-Programmable Temperature Setpoint
2.08C Setpoint Accuracy
4.08C Preset Hysteresis
Wide Supply Range (+2.7 V dc to +7.0 V dc)
Wide Temperature Range (–408C to +1508C)
Low Power Dissipation (230 mW @ 3.3 V)
APPLICATIONS
Industrial Process Control
Thermal Control Systems
CPU Monitoring (i.e., Pentium)
Computer Thermal Management Circuits
Fan Control
Handheld/Portable Electronic Equipment
GENERAL DESCRIPTION
The AD22105 is a solid state thermostatic switch. Requiring
only one external programming resistor, the AD22105 can be set
to switch accurately at any temperature in the wide operating
range of –40°C to +150°C. Using a novel circuit architecture,
the AD22105 asserts an open collector output when the ambient
temperature exceeds the user-programmed setpoint temperature.
The AD22105 has approximately 4°C of hysteresis which prevents
rapid thermal on/off cycling.
Thermostatic Switch
AD22105
FUNCTIONAL BLOCK DIAGRAM
AD22105
R
PULL–UP
OUT
GND
NC
1
2
3
4
The AD22105 is designed to operate on a single power supply
voltage from +2.7 V to +7.0 V facilitating operation in battery
powered applications as well as in industrial control systems.
Because of low power dissipation (230 µW @ 3.3 V), selfheating errors are minimized and battery life is maximized.
An optional internal 200 kΩ pull-up resistor is included to
facilitate driving light loads such as CMOS inputs.
Alternatively, a low power LED indicator may be driven directly.
200kΩ
TEMPERATURE
SENSOR
SET–
POINT
8
NC
V
S
7
R
6
SET
NC
5
+2.7V TO +7.0V
8
12
OUT
Figure 1. Typical Application Circuit
REV. 0
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.
65
7
AD22105
TOP VIEW
4
3
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
R
SET
© Analog Devices, Inc., 1996
AD22105–SPECIFICATIONS
(VS = 3.3 V, TA = +258C, R
= internal 200 kV, unless otherwise noted)
LOAD
Parameter Symbol Conditions Min Typ Max Units
TEMPERATURE ACCURACY
Ambient Setpoint Accuracy ACC ±0.5 ±2.0 °C
Temperature Setpoint Accuracy ACC
T
Power Supply Rejection PSR +2.7 V1 < V
–40°C ≤ TA ≤ +125°C ±3.0 °C
< +7.0 V ±0.05 ±0.15 °C/V
S
HYSTERESIS
Hysteresis Value HYS 4.1 °C
OPEN COLLECTOR OUTPUT
Output Low Voltage V
OL
I
= 5 mA 250 400 mV
SINK
POWER SUPPLY
Supply Range V
Supply Current, Output “LOW” IS
Supply Current, Output “HIGH” IS
INTERNAL PULL-UP RESISTOR R
TURN-ON SETTLING TIME t
NOTES
1
The AD22105 will operate at voltages as low as +2.2 V.
Specifications subject to change without notice.
- kΩ
R
80
75
70
65
60
55
50
45
40
SET
35
30
25
20
15
10
5
0
–50 150–25
ON
S
ON
OFF
PULL-UP
39MΩ °C
= ––––––––––––——— – 90.3kΩ
R
SET
T
(°C) + 281.6 °C
SET
25 50 75 100 125
0
SET POINT TEMPERATURE – °C
+2.7 +7.0 V
120 µA
90 µA
140 200 260 kΩ
5 µs
Figure 2. Setpoint Resistor Values
REV. 0–2–
AD22105
1
2
3
4
8
7
6
5
NC = NO CONNECT
AD22105
R
PULL-UP
NC
R
SET
V
S
NC
OUT
GND
NC
TOP VIEW
(Not to Scale)
ABSOLUTE MAXIMUM RATINGS*
PIN CONFIGURATION
Maximum Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . +11 V
Maximum Output Voltage (Pin 2) . . . . . . . . . . . . . . . . +11 V
Maximum Output Current (Pin 2) . . . . . . . . . . . . . . . 10 mA
Operating Temperature Range . . . . . . . . . . –50°C to +150°C
Dice Junction Temperature . . . . . . . . . . . . . . . . . . . . +160°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +160°C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . +300°C
*Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. This is a stress rating only and functional
operation of the device at these or any other conditions above those listed in the
operational sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
PIN DESCRIPTION
Pin No. Description
ORDERING GUIDE
Package Package
Model Description Option
AD22105AR 8-Lead SOIC SO-8
AD22105AR-REEL7 8-Lead SOIC SO-8
1R
2 OUT
3 GND
4 No Connection
5 No Connection
6R
7V
Internal 200 kΩ (Optional)
PULL-UP,
, Temperature Setpoint Resistor
SET
S
8 No Connection
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD22105 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
REV. 0 –3–
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