ETC AS2431M

AS2431
Micropower SOT-23, 2.5V Precision
Adjustable Shunt Regulator
FEATURES
APPLICATIONS
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Voltage Tolerance ............................................... 0.5%
Wide Operating Current ..................... 1ma to 100mA
Extended Temperature Range ...............0°°C to 105°°C
Low Temperature Coefficient ........................30 ppm/°C
Offered In Small Low Power SOT-23 Package
Low Output Noise
Battery Operating Equipment
Adjustable Supplies
Switching Power Supplies
Error Amplifiers
Single Supply Amplifier
Monitors / VCR / TV
Personal Computers
PRODUCT DESCRIPTION
The AS2431 is a 3-terminal Adjustable Shunt Voltage Regulator providing a highly accurate 0.5% bandgap reference. AS2431 acts as
an open-loop error amplifier with a 2.5V temperature compensation reference. The AS2431 thermal stability, wide operating current
(100mA) and temperature range (105°C) makes it suitable for all variety of applications that are looking for a low cost solution with
high performance. AS2431 tolerance of 0.5% 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 make this precision reference an excellent error amplifier.
The AS2431 is a direct replacement for the AS431 and TL431 in low voltage, low current applications.
ORDERING INFORMATION
SOT-23
5-PIN
AS2431YM5
SOT-23
3-PIN
AS2431YM
TEMP OPER
RANGE
0°C to 105°C
Y = Output Accuracy (Y= A or Blank)
PIN CONNECTIONS
SOT-23-5
SOT-23-5
N/C
N/C
N/C
N/C
5
4
5
4
3
1
AS2431
1
REF
2
ANODE
AS2432
CATHODE
Top View
0.5% Device
REF
2
SOT-23
SOT-23
ANODE
ANODE
AS2431
AS2432
3
ANODE
Top View
1% Device
CATHODE
REF
CATHODE
Top View
0.5% Device
REF
CATHODE
Top View
1% Device
Rev. 10/11/00
AS2431
CATHODE (K)
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, SOT-23
Junction Temperature
Storage Temperature
Lead Temperature (Soldering 10 sec.)
Symbol
VKA
IAK
IKA
IREF
PD
TJ
TSTG
TL
Rating
18
1
100
1
300
150
- 65 to 150
300
Units
V
A
mA
mA
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
Current Voltage
Cathode Current
Symbol
VKA
IK
Rating
VREF to 18
10
TYPICAL THERMAL RESISTANCES
Unit
V
mA
Package
SOT-23
0JA
575° C/W
0JC
150° C/W
Typical Derating
1.7 mW/°C
Rev. 10/11/00
AS2431
ELECTRICAL CHARACTERISTICS are guaranteed over full junction temperature range (0°C to 105°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.
AS2431A
AS2431
Test
Parameter
Symbol Test Condition
Min
Typ
Max
Min
Typ
Max
Unit
Circuit
Reference Voltage
VREF
2.487 2.500 2.513 2.474 2.500 2.526
V
1
TA = 25° C
Over Temp.
2.480
2.520 2.460
2.540
V
1
TC
0.07
0.20
0.07
0.20
1
∆VREF with Temp*
mV/°C
Ratio of Change in VREF
-2.7
-1.01
-2.7
-1.01
VREF to 10 V
∆VREF
mV/V
2
to Cathode Voltage
10 V to 18 V
-2
-0.4
0.3
-2
-0.4
0.3
∆VK
Reference Input Current
IREF
0.7
4
0.7
4
2
µA
IREF Temp Deviation
0.4
1.2
0.4
1.2
2
∆IREF
µA
Min IK for Regulation
IK (MIN)
0.4
1
0.4
1
mA
1
Off State Leakage
IK (OFF)
VREF = 0V
0.04
500
0.04
500
nA
3
VKA = 18V
Dynamic Output
f < 1 kHz IK =
ZKA
0.15
0.5
0.15
0.5
1
Ω
Impedance
1 to 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
100 125
∆TA
TC in ppm/°C =
∆VREF
VREF at 25°C
)
x 100
∆TA
)
0
)
0
ppm
Calculating Average Temperature Coefficient (TC)
∆VREF
VREF at 25°C
)
x 106
∆TA
Temperature (°C)
0.06 mV/°C
0.002 %/°C
24 ppm/°C
Rev. 10/11/00
AS2431
Test Circuits
VIN
VKA = VREF
IREF
IK
VIN
VKA
R1
IK
VIN
VKA
IK (OFF)
(VREF)
R2
Figure 1a. Test Circuit 1
Figure 1b. Test Circuit 2
Figure 1c. Test Circuit 3
Rev. 10/11/00
AS2431
TYPICAL PERFORMANCE CURVES
High Current Operating Characteristics
Low Current Operating Characteristics
900
150
VKA = VREF
Temperature Range: - 0 to 105 °C
800
700
100
600
500
400
105 °C
300
25 °C
200
75
IK - Cathode Current (mA)
µA)
IK - Cathode Current (µ
VKA = V REF
Temperature Range: - 0 to 105 °C
125
50
25
0
-25
-0°C
100
-50
0
-75
-100
-100
-200
-1.0
0
1.0
2.0
-2
3.0
-1
0
2
3
Figure 3
Figure 2
Off State Leakage
Reference Voltage vs. Ambient Temperature
100
2.53
VKA = 18V
VREF = 0V
V KA= V REF
IK = 10 mA
2.52
VREF - Reference Voltage (V)
IZ off - Off State Cathode Current (nA)
1
VKA - Cathode Voltage (V)
VKA - Cathode Voltage (V)
10
1
0.1
2.51
2.50
VREF = 2.500 V at 25 °C
2.49
2.48
2.47
2.46
0.01
-60
-30
0
30
60
TA - Ambient Temperature ( °C)
Figure 4
90
120
2.45
-60
-30
0
30
60
90
120
TA - Ambient Temperature ( °C)
Figure 5
Rev. 10/11/00
AS2431
TYPICAL PERFORMANCE CURVES
Reference Input Current
VREF - Change in Reference Voltage (mV)
IREF - Reference Input Currentµ(A)
R1 = 10 k Ω
R2 = ∞
IK = 10 mA
2.5
Reference Voltage Line Regulation
0
3.0
2.0
1.5
1.0
0.5
-10
0 °C
-20
25 °C
75 °C
-30
105 °C
-40
-50
0
-60
-30
0
30
60
90
120
0
3
6
9
12
15
TA - Ambient Temperature ( °C)
VKA - Cathode Voltage (V)
Figure 6
Figure 7
18
Low Frequency Dynamic Output Impedance
Noise Voltage
0.150
70
VKA = VREF
IKA = 1 to 100 mA
f < 1 kHz
60
ZKA - Dynamic Impedance (Ω )
0.125
Noise Voltage nV/√Hz
50
40
30
20
0.100
0.075
0.050
0.025
10
V KA = V REF
IK = 10 mA
TA = 25°C
0.0
0
-60
10
100
1k
f - Frequency (Hz)
Figure 8
10 k
100 k
-30
0
30
60
90
120
TA - Free Air Temperature
Figure 9
Rev. 10/11/00
AS2431
TYPICAL PERFORMANCE CURVE
Dynamic Output Impedance
100
ZKA - Dynamic Impedance
TA = 25 °C
IK = 1 to 100 mA
10
1.0
0.1
0.01
1k
10 k
100 k
10 M
1M
f - Frequency (Hz)
Figure 10
Small Signal Voltage Gain vs. Frequency
70
AV - Small Signal Voltage Gain (dB)
Temperature Range: -0 to 105 °C
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. 10/11/00
AS2431
TYPICAL PERFORMANCE CURVES
Pulse Response
6
INPUT
Input and Output Voltages (V)
5
INPUT
MONITOR
220 Ω
OUT
4
3
OUTPUT
50 Ω
fP = 100 kHz
2
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
80
IK - Cathode Current (mA)
70
C
60
150 Ω
IK
50
40
STABILITY
REGION
CL
30
A
20
TA = 25 °C
10
10 k
B
D
0
100
101
102
103
104
105
CL - Load Capacitance (pF)
106
107
Figure 13
Rev. 10/11/00