SEMICONDUCTOR
AS1431
Precision Adjustable Shunt Reference
Description
The AS1431 is a three-terminal adjustable shunt regulator providing a
highly accurate 0.4% bandgap reference. The adjustable shunt regulator
is ideal for a wide variety of linear applications that can be implemented
using external components to obtain adjustable currents and voltages.
In the standard shunt configuration, the combination of low temperature
coefficient (TC), sharp turn-on characteristics, low output impedance and
programmable output voltage make this precision reference a perfect
zener diode replacement.
The AS1431 is characterized to operate over the full automotive tem-
perature range of Ð55 to 125¡C and is now available in the SOT-23 (5L)
package.
Features
¥
¥
¥
¥
¥
¥
¥
Temperature-compensated: 30 ppm/¡C
Trimmed 0.4% bandgap reference
Internal amplifier with 150 mA capability
Temperature range: Extended to Ð55
to125¡C
Low frequency dynamic output
impedance: < 150 m½
Low output noise
Robust ESD protection
Pin Configuration Ñ
Top view
TO-92 (LP)
CATHODE
CATHODE
ANODE
ANODE
REFERENCE
ANODE
N/C
2
3
4
1
SOIC (D)
8
7
6
5
REFERENCE
ANODE
ANODE
N/C
SOT-89 (S)
SOT-23/5L (DBV)
N/C
N/C
CATHODE
ANODE
CATHODE
REFERENCE
ANODE
REFERENCE
Ordering Information
AS1431 D R4 D 7
Circuit Type:
Precision Adjustable
Shunt Regulator
Temperature Range:
D = –55°C to +125°C
Bandgap Tolerance:
R4 =
±0.4%
Packaging Option:
A = Ammo Pack
B = Bulk
T = Tube
7 = Tape and Reel (7" Reel Dia)
13 = Tape and Reel (13" Reel Dia)
Package Style:
D = SOIC
DBV = SOT-23/5L
LP = TO-92
S = SOT-89
ASTEC Semiconductor
1
AS1431
Functional Block Diagram
Precision Adjustable Shunt Reference
CATHODE (K)
REFERENCE
(R)
+
Ð
2.5 V
ANODE (A)
Absolute Maximum Ratings
Parameter
Cathode-Anode Reverse Breakdown
Anode-Cathode Forward Current
Operating Cathode Current
Reference Input Current
Continuous Power Dissipation at 25¡C
TO-92
8L SOIC
SOT-89
SOT-23/5L
Junction Temperature
Storage Temperature
Lead Temperature Soldering 10 Seconds
T
J
T
STG
T
L
Symbol
V
KA
I
AK
I
KA
I
REF
P
D
775
750
1000
200
150
Ð65 to 150
300
mW
mW
mW
mW
¡C
¡C
¡C
Rating
37
1
250
10
Units
V
A
mA
mA
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.
Recommended Conditions
Parameter
Cathode Voltage
Cathode Current
Symbol
V
KA
I
K
Rating
V
REF
to 20
10
Unit
V
mA
Typical Thermal Resistances
Package
TO-92
SOIC
SOT-89
θ
JA
160¡C/W
175¡C/W
110¡C/W
θ
JC
80¡C/W
45¡C/W
8¡C/W
150¡C/W
Typical Derating
6.3 mW/¡C
5.7 mW/¡C
9.1 mW/¡C
1.7 mW/¡C
SOT-23/5L 575¡C/W
ASTEC Semiconductor
2
Precision Adjustable Shunt Reference
Electrical Characteristics
AS1431
Electrical Characteristics are guaranteed over full junction temperature range (Ð55 to 125¡C). Ambient temperature must be derated
based on power dissipation and package thermal characteristics. The conditions are: V
KA
= V
REF
and I
K
= 10 mA unless otherwise stated.
Parameter
Reference Voltage
Symbol
V
REF
TC
ÆV
REF
I
REF
ÆI
REF
I
K(min)
I
K(off)
Z
KA
V
REF
= 0 V,
V
KA
= 36 V
f ² 1 kHz
I
K
= 1 to 100 mA
ÆV
K
= 3 V to 36 V
R
1
= 10 k ½; R
2
= °
Over temp.
Ð2
Test Condition
T
A
= 25¡C
Over temp.
ÆV
REF
with Temp*
Ratio of Change in V
REF
to
Cathode Voltage
Reference Input Current
I
REF
Temp Deviation
Min I
K
for Regulation
Off State Leakage
Dynamic Output Impedance
Min.
2.490
2.470
0.06
Ð1.1
0.7
0.4
0.4
0.04
0.15
1.9
1.2
1
500
0.2
Typ.
2.500
Max.
2.510
2.530
0.16
Unit
V
V
mV/¡C
mV/V
µA
µA
mA
nA
½
Circuit
1
1
1
2
2
2
1
3
1
*Calculating Average Temperature Coefficient (TC)
Average Temperature Coefficient
ppm
0
0
%
0
• TC in mV/°C =
∆V
REF
–10
5000
0.5
∆T
• TC in %/°C =
mV
∆V
REF
(mV)
∆T
A
∆V
REF
V
REF
at 25°C
∆T
A
∆V
REF
–55 –25
0
25 50
75
Temperature (°C)
100 125
• TC in ppm/°C =
V
REF
at 25°C
∆T
A
X 100
–20
X 10
6
0.06 mV/°C
0.002%/°C
24 ppm/°C
ASTEC Semiconductor
3
AS1431
Test Circuits
V
IN
V
KA
= V
REF
V
IN
Precision Adjustable Shunt Reference
V
KA
V
IN
V
KA
I
REF
I
K
I
K
R
1
I
REF
(V
REF
)
R
2
I
K (OFF)
Figure 1a. Test Circuit 1
Figure 1b. Test Circuit 2
Figure 1c. Test Circuit 3
ASTEC Semiconductor
4
Precision Adjustable Shunt Reference
Typical Performance Curves
AS1431
Low Current Operating Characteristics
900
800
700
I
K
– Cathode Current (mA)
600
I
K
– Cathode Current (µA)
500
400
300
200
100
0
–100
–200
–1.0
0
1.0
2.0
3.0
125°C
25°C
–55°C
V
KA
= V
REF
Temperature Range: –55 to 125°C
150
125
100
75
50
25
0
–25
–50
–75
–100
–2
High Current Operating Characteristics
V
KA
= V
REF
Temperature Range: –55 to 125°C
–1
0
1
2
3
V
KA
– Cathode Voltage (V)
V
KA
– Cathode Voltage (V)
Figure 2
Figure 3
Off State Leakage
100
V
KA
= 36 V
V
REF
= 0 V
I
Z
off – Off State Cathode Current (nA)
V
REF
– Reference Voltage (V)
10
2.53
2.52
2.51
2.50
Reference Voltage vs Ambient Temperature
V
KA
= V
REF
I
K
= 10 mA
V
REF
= 2.500 V at 25°C
2.49
2.48
2.47
2.46
1
0.1
0.01
–60
–30
0
30
60
90
120
2.45
–60
–30
0
30
60
90
120
T
A
– Ambient Temperature (°C)
T
A
– Ambient Temperature (°C)
Figure 4
Figure 5
ASTEC Semiconductor
5
京公网安备 11010802033920号
EEWORLD
