ETC AS1431M1

AS1431
Precision Adjustable Shunt Regulator
FEATURES
APPLICATIONS
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Voltage Tolerance ................................................ 0.4%
Wide Operating Current .....................1mA to 150mA
Extended Temperature Range ........... -55°°C to 125°°C
Low Temperature Coefficient ........................30 ppm/°C
Improved Replacement in Performance for LT1431
Offered In Small Low Power SOT-89 Package
Low Output Noise
Battery Operating Equipment
Adjustable Supplies
Switching Power Supplies
Error Amplifiers
Single Supply Amplifiers
Monitors / VCR / TV
Personal Computers
PRODUCT DESCRIPTION
The AS1431 is a 3-terminal Adjustable Shunt Voltage Regulator providing a highly accurate 0.4% bandgap reference. AS1431 acts as
an open-loop error amplifier with a 2.5V temperature compensation reference. The AS1431 thermal stability, wide operating current
(150mA) and temperature range (125°C) makes it suitable for all varieties of applications that are looking for a low cost solution with
high performance. AS1431 tolerance of 0.4% is proven to be sufficient to overcome all of the other errors in the system to
virtually eliminate the need for trimming in the power supply manufactures assembly line and contribute a significant Cost
Savings.
In the standard shunt configuration, the combination of low temperature coefficient (T.C.), sharp turn-on characteristics, low output
impedance and programmable output voltage that makes this precision reference an excellent error amplifier.
The AS1431 is a direct improved replacement for the AS431 and TL431 in low voltage, low current applications.
PIN CONFIGURATIONS
Standard Pinout
8-Pin Surface Mount (S)
CATHODE
1
8
REF
ANODE
2
7
ANODE
ANODE
3
6
ANODE
N/C
4
5
N/C
AS1431
Top View
SOT-23-5 (M5)
REF
ANODE
5
4
SOT-89 (M1)
1
N/C
2
N/C
2
3
AS1431
AS1431
1
TO-92 (N)
3
CATHODE
Top View
REF
1
2
ANODE
3
CATHODE
Front View
REF
CATHODE
ANODE
Bottom View
Rev. 10/5/00
AS1431
ORDERING INFORMATION
Part
Number
AS1431N
AS143S1/S2
AS1431M1
AS1431M5
Temperature
Range
-55°C to 125°C
-55°C to 125°C
-55°C to 125°C
-55°C to 125°C
CATHODE (K)
Package
Type
TO-92
SOIC
SOT-89
SOT-23-5
REFERENCE
(R)
+
2.5V
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
SOT-23
8L SOIC
SOT-89
Junction Temperature
Storage Temperature
Lead Temperature (Soldering 10 sec.)
Symbol
VKA
IAK
IKA
IREF
PD
TJ
TSTG
TL
Rating
37
1
250
10
Units
V
A
mA
mA
775
200
750
1000
150
- 65 to 150
300
mW
mW
mW
mW
°C
°C
°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 sections 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
VKA
IK
RATING
VREF to 20
10
TYPICAL THERMAL RESISTANCES
UNIT
V
mA
PACKAGE
TO-92
SOT-23
SOIC
SOT-89
0JA
160° C/W
575° C/W
175° C/W
110° C/W
0JC
80° C/W
150° C/W
45° C/W
8° C/W
TYPICAL DERATING
6.3 mW/°C
1.7 mW/°C
5.7 mW/°C
9.1 mW/°C
Rev. 10/5/00
AS1431
ELECTRICAL CHARACTERISTICS are guaranteed over full junction temperature range (-55°C to 125°C). Ambient
temperature must be derated based on power dissipation and package thermal characteristics. The conditions are: VKA = VREF and
IK = 10mA, unless otherwise specified.
Parameter
Symbol
Test Conditions
Test Circuit
Min
Typ
Max
Units
Reference Voltage
VREF
1
2.490
2.500
2.510
V
TA = 25°C
Over Temp.
1
2.465
2.535
V
VREF with Temp*
TC
1
0.06
0.16
mV/°
C
Ratio of Change in VREF
VREF
VK = 3V to 36V
2
-2
-1.1
mV/V
to Cathode Voltage
Reference Input Current
IREF
RI = 10 k; R2 =
2
0.7
1.9
µA
IREF Temp Deviation
IREF
Over Temp.
2
0.4
1.2
µA
Min IK for Regulation
IK (min)
1
0.4
1
mA
Off State Leakage
IK (off)
VREF = 0V, VKA =
3
0.04
250
nA
36V
Dynamic Output
ZKA
f < 1 kHz IK 1 to
1
0.15
0.2
Ω
Impedance
100mA
mV
%
0
∆VREF
∆Τ
-10
5000
TC in %/°C =
0.5
-20
∆VREF (mV)
TC in mV/°C =
-55
-25
0
25
50
75
∆TA
TC in ppm/°C =
100 125
∆VREF
VREF at 25°C
)
0
)
0
ppm
Calculating Average Temperature Coefficient (TC)
)
x 100
∆TA
∆VREF
VREF at 25°C
)
x 106
∆TA
Temperature (°C)
0.06 mV/°C
0.002 %/°C
24 ppm/°C
TEST CIRCUITS
VIN
VKA = VREF
IREF
IK
VIN
VKA
R1
(VREF)
IK
VIN
VKA
IK (OFF)
IREF
R2
Figure 1a. Test Circuit 1
Figure 1b. Test Circuit 2
Figure 1c. Test Circuit 3
Rev. 10/5/00
AS1431
TYPICAL PERFORMANCE CURVES
High Current Operating Characteristics
Low Current Operating Characteristics
900
150
VKA = VREF
Temperature Range: - 55 to 125 °C
800
700
IK - Cathode Current (mA)
100
600
IK - Cathode Current (µA)
VKA = VREF
Temperature Range: - 55 to 125 °C
125
500
400
125 °C
300
25 °C
200
-55 °C
100
75
50
25
0
-25
-50
0
-75
-100
-100
-200
-1.0
0
1.0
2.0
-2
3.0
-1
VKA - Cathode Voltage (V)
Figure 2
1
2
3
Figure 3
Off State Leakage
Reference Voltage vs. Ambient Temperature
2.53
100
VKA = 18V
VREF = 0V
VKA = VREF
IK = 10
mA
2.52
10
VREF - Reference Voltage (V)
IZ off - Off State Cathode Current (nA)
0
VKA - Cathode Voltage (V)
1
0.1
2.51
2.50
VREF = 2.500 V at 25 °C
2.49
2.48
2.47
2.46
0.01
2.45
-60
-30
0
30
60
TA - Ambient Temperature ( °C)
Figure 4
90
120
-60
-30
0
30
60
90
120
TA - Ambient Temperature ( °C)
Figure 5
Rev. 10/5/00
AS1431
TYPICAL PERFORMANCE CURVES
Reference Input Current
Reference Voltage Line Regulation
3.0
0
VREF - Change in Reference Voltage (mV)
IREF - Reference Input Currentµ(A)
R1 = 10 kΩ
R2 = ∞
IK = 10 mA
2.5
2.0
1.5
1.0
0.5
-10
-55 °C
0 °C
-20
25 °C
75 °C
-30
125 °C
-40
-50
0
-60
-30
0
30
60
90
120
0
3
6
TA - Ambient Temperature ( °C)
Figure 6
9
12
15
18
21
24
27
30
VKA - Cathode Voltage (V)
Figure 7
Noise Voltage
Low Frequency Dynamic Output Impedance
70
0.150
VKA = VREF
IKA = 1 to 100 mA
f < 1 kHz
60
()
ZKA - Dynamic Impedance Ω
Noise Voltage nV/vHz
0.125
50
40
30
20
0.100
0.075
0.050
0.025
10
VKA = VREF
IK = 10 mA
TA = 25 C
0.0
0
10
100
1k
f - Frequency (Hz)
Figure 8
10 k
100 k
-60
-30
0
30
60
90
120
TA - Free Air Temperature
Figure 9
Rev. 10/5/00
AS1431
TYPICAL PERFORMANCE CURVES
Dynamic Output Impedance
100
ZKA - Dynamic Impedance (Ω)
TA = 25 °C
IK = 1 to 100 mA
10
1.0
0.1
0.01
1k
10 k
100 k
1M
10 M
f - Frequency (Hz)
Figure 10
Small Signal Voltage Gain vs. Frequency
70
Temperature Range: -55 to 125 °C
AV - Small Signal Voltage Gain (dB)
60
IK = 10 mA
50
OUT
40
15 k
IK
230 Ω
9 µF
30
8.25 k
20
GND
10
0
1k
10 k
100 k
f - Frequency (Hz)
1M
10 M
Figure 11
Rev. 10/5/00
AS1431
TYPICAL PERFORMANCE CURVES
Pulse Response
6
INPUT
5
Input and Output Voltages (V)
INPUT
MONITOR
220 Ω
OUT
4
3
OUTPUT
50 Ω
2
fP = 100 kHz
1
GND
0
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
t - Time ( µs)
Figure 12
Stability Boundary Conditions
100
A:
B:
C:
D:
90
V KA = V REF
V KA = 5V at I K = 10 mA
V KA = 10V at I K = 10 mA
V KA = 15V at I K = 10 mA
IK - Cathode Current (mA)
80
70
C
150 Ω
60
IK
50
40
STABILITY
REGION
CL
30
10 k
A
20
B
T A = 25 °C
10
D
0
10 0
10 1
10 2
10 3
10 4
10 5
10 6
10 7
CL - Load Capacitance (pF)
Figure 13
Rev. 10/5/00