Aimtron AT431Z 1.24v low-voltage adjustable precision shunt regulator Datasheet

AT431
Preliminary Product Information
1.24V 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 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
Aimtron reserves the right without notice to change this circuitry and specifications.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
1
AT431
Preliminary Product Information
1.24V Low-Voltage Adjustable Precision
Shunt Regulator
Equivalent Schematic
Pin Assignments
Ordering Information
Part number
Package
AT431Z
TO-92
Date Code
AT431UN
SOT-23
Date Code
AT431UN_GRE
SOT-23, Green
,Date Code with one bottom line
Marking
: Date Code
*For more marking information, contact our sales representative directly
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
2
AT431
Preliminary Product Information
1.24V 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
IK=10mA (Figure 1)
VKA= Vref
IK=10mA (Figure 1)
mV/V VKA= Vref to 12V
IK=10mA (Figure 2)
µA IK=10mA
R1=10KΩ (Figure 2)
µA IK=10mA R1=10KΩ
R2=open
(Figure 2)
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
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
3
AT431
Preliminary Product Information
1.24V Low-Voltage Adjustable Precision
Shunt Regulator
Parameter Measurement Information
Figure 2. Test Circuit for VKA>Vref
Figure 1. Test Circuit for VKA=Vref
VO= VKA=Vref *(1+R1/R2)+Iref *R1
VO= VKA=Vref
Figure 3. Test Circuit for IK(off)
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
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AT431
Preliminary Product Information
1.24V Low-Voltage Adjustable Precision
Shunt Regulator
Figure 4.
Figure 6.
Figure 5.
Figure 7.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
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AT431
Preliminary Product Information
1.24V Low-Voltage Adjustable Precision
Shunt Regulator
Figure 8.
Figure 9.
Figure 10.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
6
AT431
Preliminary Product Information
1.24V Low-Voltage Adjustable Precision
Shunt Regulator
Application Circuit
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
7
AT431
Preliminary Product Information
1.24V 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.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
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AT431
Preliminary Product Information
1.24V 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。
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
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AT431
Preliminary Product Information
1.24V 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
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
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AT431
Preliminary Product Information
1.24V Low-Voltage Adjustable Precision
Shunt Regulator
Reflow Profiles
Profile Feature
Sn-Pb Eutectic Assembly
Large Body
Small Body
Pkg. thickness ≥2.5mm Pkg. thickness <2.5mm
3
or Pkg. volume ≥350mm3 or Pkg. volume <350mm
Average ramp-up rate
Pb-Free Assembly
Large Body
Small Body
Pkg. thickness ≥2.5mm or
Pkg. volume ≥350mm3
Pkg. thickness ≥2.5mm
or Pkg. volume ≥350mm3
3°C/second max.
3°C/second max.
-Temperature Min(Tsmin)
100°C
150°C
-Temperature Max (Tsmax)
150°C
200°C
60-120 seconds
60-180 seconds
(TL to TP)
Preheat
-Time (min to max)(ts)
Tsmax to TL
3°C/second max.
-Ramp-up Rate
Time maintained above:
-Temperature (TL)
-Time (tL)
Peak Temperature(TP)
Time within 5°C
Temperature (tP)
of
actual
Ramp-down Rate
Time 25°C to Peak Temperature
Peak
183°C
217°C
60-150 seconds
60-150 seconds
225+0/-5°C
240+0/-5°C
245+0/-5°C
250+0/-5°C
10-30 seconds
10-30 seconds
10-30 seconds
20-40 seconds
6°C/second max.
3°C/second max.
6 minutes max.
8 minutes max.
*All temperatures refer to topside of the package, measured on the package body surface.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
2/8/2006 REV:1.1
Email: [email protected]
11
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