ETC1 AT431Z Low-voltage adjustable precision shunt regulator Datasheet

AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Features
Description
˙Low-Voltage Operation: Down to 1.24V
˙1% Reference-Voltage Tolerance
˙Adjustable Output Voltage, Vo=Vref to 12V
˙Low Operational Cathode Current….50μA
˙0.25Ω Typical Output Impedance
˙SOT-23-3 , SOT-23-5 and TO-92 Packages
The AT431 is low-voltage three-terminal
adjustable voltage reference with specified
thermal stability over applicable commercial
temperature ranges. Output voltage may be set to
any value between Vref (1.24V) and 12V with
two external resistors (see Figure 2).
Application
When used with an optocoupler, the AT431 is
ideal voltage reference in isolated feedback
circuits for 1.8V to 12 V switching-mode power
supplies. This device has typical output
impedance of 0.20Ω. Active output circuitry
provides a very sharp turn-on characteristic,
making the AT431 excellent replacements for
low-voltage zener diodes in many applications,
including onboard regulation and adjustable
power supplies.
˙Linear Regulators
˙Voltage Reference for Power Circuit
Block Diagram and Symbol
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
1
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Equivalent Schematic
Pin Assignments
Ordering Information
Part number
AT431Z
AT431X
AT431UN
AT431UT
AT431C
*
Package
TO-92
SOT-25
SOT-23
SOT-23
SOT-89
Marking
Z
X
N
T
C
: Data Code
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
2
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Absolute maximum ratings (TA = 25oC)
Parameter
Cathode voltage
Continuous cathode current range
Reference Current
Operating temperature
Storage temperature
Package thermal impedance θJA
Symbol
VKA
IK
IREF
TOPR
TSTG
SOT-23-5
SOT-23-3
TO-92
Power Dissipation
Limits
12
-20~20
-0.05~3
-30~+85
-55~+150
347
unit
V
mA
mA
o
C
o
C
o
C/W
156
(TJ(max)-TA)/ θJA
PD
Stresses beyond those listed under “ absolute maximum ratings” may cause permanent damage to the
device. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Recommend operating condtion
Parameter
Cathode voltage VKA
Continuous cathode current range IK
Operating free-air temperature range TA
min
Vref
0.05
0
Max
12
15
70
unit
V
mA
o
C
Electrical characteristics (unless otherwise noted)
Parameter
Reference Voltage
Vref deviation over full
temperature range
Ratio of Vref change in
cathode voltage change
Reference terminal
current
Iref deviation over full
temperature range
Minimum cathode current
for regulation
Off-state cathode current
Dynamic impedance
Symbol
Vref (TA = 25oC)
Vref (TA = full
o
range 0~70 C)
Vref(dev)
Min.
1.228
1.221
Typ.
1.24
-
Max.
1.252
1.259
Unit
V
V
-
4
20
mV
∆ Vref /∆ VKA
-
-1.5
-2.7
Iref
-
0.15
0.5
Iref(dev)
-
0.05
0.3
IK(min)
-
40
50
IK(off)
-
0.001
0.1
µA
| ZKA |
-
0.20
0.4
Ω
Conditions
VKA= Vref
(Figure 1)
IK=10mA
VKA= Vref
IK=10mA
(Figure 1)
mV/V VKA= Vref to 12V
IK=10mA
(Figure 2)
µA IK=10mA
(Figure 2)
R1=10KΩ
µA IK=10mA R1=10KΩ
(Figure 2)
R2=open
µA VKA= Vref (Figure 1)
VKA=12V
Vref =0V
(Figure 3)
VKA= Vref f≤1KHz
IK=0.1mA to 15mA
(Figure 1)
* The dynamic impedance is defined as : |ZKA| = ∆ VKA /∆ IKA
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
3
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Parameter Measurement Information
Figure 1. Test Circuit for VKA=Vref
Figure 2. Test Circuit for VKA>Vref
VO= VKA=Vref
VO= VKA=Vref *(1+R1/R2)+Iref *R1
Figure 3. Test Circuit for IK(off)
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
4
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Figure 4.
Figure 6.
Figure 5.
Figure 7.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
5
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Figure 8.
Figure 9.
Figure 10.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
6
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Application Circuit
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
7
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
8
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Above shows the AT4311 used in a 3.3V isolated flyback supply. Output voltage Vo can be as low
as reference voltage Vref (1.24V±1%). The output of the regulator, plus the forward voltage drop
of the optocoupler LED (1.24+1.4=2.64V), determine the minimum voltage that can be regulated
in an isolated in an isolated supply configuration. Regulated voltage as low as 2.7V is possible
using the circuit.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
9
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Package Information
SOT-23
SYMBOL
A
A1
B
C
D
E
E
H
L
S
R
MILLIMETERS
MIN
MAX
0.787
1.194
0.025
0.127
0.356
0.559
0.086
0.152
2.667
3.048
1.194
1.397
1.778
2.032
2.083
2.489
0.102
0.305
0.432
0.559
8。
0。
INCHES
MIN
0.031
0.001
0.014
0.0034
0.105
0.047
0.070
0.082
0.004
0.017
0。
MAX
0.047
0.005
0.022
0.006
0.120
0.055
0.080
0.098
0.012
0.022
8。
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
10
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
SOT-25
SYMBOL
A
A1
A2
b
C
D
E
E1
L
e
E1
r
INCHES
MIN
0.035
0.000
0.035
0.010
0.003
0.110
0.102
0.059
0.014
MAX
0.057
0.006
0.051
0.020
0.008
0.122
0.118
0.069
0.022
0.037ref
0.075ref
00
100
MILLIMETERS
MIN
MAX
0.90
1.45
0.00
0.15
0.90
1.30
0.25
0.50
0.08
0.20
2.80
3.10
2.60
3.00
1.50
1.75
0.35
0.55
0.95ref
1.90ref
00
100
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
11
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
SOT-89
SYMBOL
A
B
B
b1
C
C1
D
D1
E
H
MILLIMETERS
MIN
MAX
1.397
1.600
0.356
0.483
2.388
2.591
0.406
0.533
-4.242
0.787
1.194
4.394
4.597
1.397
1.753
1.448
1.549
0.381
0.432
INCHES
MIN
0.055
0.014
0.094
0.016
-0.031
0.173
0.055
0.057
0.015
MAX
0.063
0.019
0.102
0.021
0.167
0.047
0.181
0.069
0.061
0.017
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
12
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
TO-92
SYMBOL
A
B
C
D
E
e
e1
L
MILLIMETERS
MIN
MAX
3.4
3.8
0.3
0.5
4.4
4.8
4.4
4.8
0.9
1.5
1.17
1.37
2.39
2.69
12
16
INCHES
MIN
0.134
0.012
0.173
0.173
0.035
0.046
0.094
0.472
MAX
0.150
0.020
0.189
0.189
0.059
0.054
0.106
0.630
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
13
AT431
Low-Voltage Adjustable Precision
Shunt Regulator
Reflow Condition (IR/Convection or VPR Reflow)
Reference JEDEC Standard J-STD-020A
Classification Reflow Profiles
Convection or
IR/Convction
Average Heating Rate(180°C to peak)
Preheat Temperature(125±20°C)
Temperature maintained above 180°C
Time within 5°C of actual Peak Temperature
Peak Temperature Range(Note 1)
Cooling Rate
Time 25°C to Peak Temperature
5°C/second max.
120 seconds max.
10~150 seconds
10~20 seconds
219~225°C or
235~240°C
6°C /second max.
6 minutes max.
VPR
10°C/second max.
60 seconds
219~225°C or
235~240°C
10°C/second max.
*1 The maximum peak temperatures for IR and VP reflow are depending on package dimensions.
Package Reflow Conditions
Pkg. Thickness ≥2.5mm and Pkg. Thickness <2.5mm
and
all bags
Pkg. Volume ≥350 mm3
Pkg. Thickness <2.5mm
and
Pkg. Volume <350 mm3
Convection 219~225°C
VPR 219~225°C
IR/Convection 219~225°C
Convection 235~240°C
VPR 235~240°C
IR/Convection 235~240°C
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
14
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