1
ASTEC Semiconductor
AS300
Shunt Temperature Sensor
Features
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Calibrated directly in Kelvin
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Linear 10 mV/¡C scale factor
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1¡C typical accuracy at 27¡C (300 K)
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Fully rated for Ð40 to 125¡C
(233 to 398 K)
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Suitable for remote applications
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Low-impedance output, 0.3 ½ for a
1 mA load
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Now available in the SOT-223 for
improved substrate temperature
sensing
Description
The AS300 is a two-terminal integrated circuit temperature sensor. It is
a precision-trimmed shunt type regulator that emulates a zener diode
in function. Its output voltage is linearly proportional to temperature in
Kelvin. The output voltage is calibrated for 3.000 V at 27¡C (300 K) and
increases by 10 mV/¡C.
The AS300 is available in four packages.The SOT-223 offers a large
heat-sink for transferring heat to the die for fast and accurate thermal
sensing. The SOT-223 is especially effective at sensing the tem-
perature of hybrid and MCM substrates. The SOT-23 is best-suited
for applications requiring a small footprint or precision force/sense
metering.
SEMICONDUCTOR
Pin Configuration Ñ Top view
Ordering Information
VTEMP
TO-92 (LP) SOT-223 (G)
GND (F)
GND (S)
VTEMP
GND (F)
GND (S)
SOIC (D)
N/C
N/C
VTEMP (F)
VTEMP (F)
GND (S)
GND (F)
N/C
N/C
1
2
3
4
8
7
6
5
SOT-23/3L (VS)
VTEMP
GND
GND
Circuit Type:
Shunt Temperature Sensor
AS300 LP A
Packaging Option:
A
B
T
7
13
Package Style:
D
G
LP
VS
= Ammo Pack
= Bulk
= Tube
= Tape and Reel (7" Reel Dia)
= Tape and Reel (13" Reel Dia)
= SOIC
= SOT-223
= TO-92
= SOT-23/3L
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ASTEC Semiconductor
AS300 Shunt Temperature Sensor
Functional Block Diagram
Pin Function Description
Pin Number
TO, SOT SOIC Function Description
1 1 GND (S) Optional sense pin ground, otherwise tie to substrate pin GND (F).
2 2 GND (F) Signal ground and circuit substrate.
3 6 VTEMP (F) Output voltage proportional to temperature. VTEMP is nominally 3.00 V
at 27¡C (300 K) and increases at 10 mV/¡C.
Ð 5 VTEMP (S) Optional sense pin for VTEMP. Available on the 8L SOIC package only.
Tie pin to VTEMP (F) if not using force/sense metering.
10 mV/°C
GND
VTEMP
+
+
–
–
Absolute Maximum Ratings
Parameter Symbol Rating Unit
Supply Current IREF 20 mA
Continuous Power Dissipation at 25¡C PD
TO-92 775 mW
SOT-223 1250 mW
8L SOIC 750 mW
SOT-23/3L 200 mW
Junction Temperature TJ150 ¡C
Operating Temperature Ð40 to 125 ¡C
Storage Temperature TSTG Ð65 to 150 ¡C
Lead Temp, Soldering 10 Seconds TL300 ¡C
Stresses greater than 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 indicated in the operational sec-
tions of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
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ASTEC Semiconductor
AS300Shunt Temperature Sensor
Typical Thermal Resistances
Package θJA θJC Typical Derating
TO-92 160¡C/W 80¡C/W 6.3 mW/¡C
SOT-223 115¡C/W 8¡C/W 8.7 mW/¡C
8L SOIC 175¡C/W 45¡C/W 5.7 mW/¡C
SOT-23/3L 575¡C/W 150¡C/W 1.7 mW/¡C
Electrical Characteristics
Electrical Characteristics are guaranteed over the full junction temperature range (Ð40 to 125¡C). Ambient temperature must be
derated based upon power dissipation and package thermal characteristics.
Parameter Symbol Test Condition Min. Typ. Max. Unit
Output Voltage VTEMP IK= 2 mA, TJ= 27¡C (300 K) 2.970 3.000 3.030 V
VTEMP IK= 2 mA, TJ= 100¡C (373 K) 3.690 3.730 3.770 V
Temperature Coefficient Error IK= 2 mA, deviation from 10 mV/¡C 40 µV/¡C
Minimum Operating Current IK(min) 0.6 mA
Output Impedance ZKA IK= 0.6 to 5.5 mA 0.3 2 ½
VTEMP
IK
VIN
Test Circuit
Figure 1
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ASTEC Semiconductor
AS300 Shunt Temperature Sensor
Typical Performance Curves
Figure 2
Figure 4
Figure 3
Figure 5
–50 –25
250 300 350 400 (K)
0 25 50 75 100 125 (°C)
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
T – Temperature
VTEMP – Output Voltage (V)
Output Voltage
IK = 2 mA
0.01 0.1 1.0 10 100
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
–0.1
Forward Characteristics
TJ = 27°C
IF – Forward Current (µA)
VF – Forward Voltage (V)
8L SOIC
TO-92
SOT-223
0 4 8 12 16 20 24
Time (s)
120
100
80
60
40
20
0
Percent of Thermal Equilibrium (%)
Thermal Response by Package in Still Air
0 2 4 6 8 10 12
120
100
80
60
40
20
0
8L SOIC
TO-92
SOT-223
Time (s)
Percent of Thermal Equilibrium (%)
Thermal Response by Package in a Stirred Oil Bath
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ASTEC Semiconductor
AS300Shunt Temperature Sensor
Typical Performance Curves
Figure 6
Figure 8
Figure 7
Figure 9
0 1 2
VTEMP – Output Voltage (V) 3 4
0
0.25
0.50
0.75
1.00
1.25
1.50
IK – Reverse Current (mA)
Operating Characteristics
100°C
27°C
0°C
0 1 2
VTEMP – Output Voltage (V) 3 4
0
100
10
1.0
1k
10k
IK – Reverse Current (µA)
Operating Characteristics
100°C
27°C
0°C
0.01 0.1 1.0 10 10 1k
1k
100
10
1.0
0.1
0.01
f – Frequency (kHz)
TJ = 27°C
IK = 2 mA
Dynamic Impedance
ZK – Output Impedance (Ω)
0 25 50 500 600
4
3
2
1
0
5
0
INPUT
VIN
1k VOUT
TJ = 27°C
OUTPUT
t – Time (µs)
Transient Response
Input and Output Voltage (V)
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ASTEC Semiconductor
AS300 Shunt Temperature Sensor
Typical Applications
15 V
9.1k 15k 20k
AS431
AS300 500
2N2907
Figure 10 Figure 11
Linear Fan Controller
Linear Fan Controller Thermostat
Fahrenheit Thermometer
Ð
+
LM358
Ð
+
LM358 Ð
+
LM339
Adjust R1 to set 0°F reading (120k)
Adjust R2 to set 100°F reading (2.7k)
R2
R1 AS1004-1.2
100 µA Full Scale
Analog Meter
130k
AS300
9 V
5k
M12 VDC, 120 mA
Brushless Fan
1.2 V
120k
91k
10k
10k
AS300 34k
IRF233
AS300
1 nF
Figure 12 Figure 13
R3
R1 R2
VCC
M12 VDC, 120 mA
Brushless Fan
A
