AQ431R
2.5V Shunt Ref/Amplifier
TO-92 and SOT23 Package
Preliminary Specification
Revision 1.6
June 15, 2007
General Description
The AQ431R is a three-terminal adjustable
shunt regulator based on a highly stable
bandgap reference and is an excellent
replacement for standard TL431 references
when used as a secondary feedback element
in Switch Mode Power Supplies.
The AQ431R meets all of the requirements of
the standard 431 specifications that are
needed to monitor the secondary output
voltage and provide the feedback signal to
the primary through an opto-coupler. It is
offered in both the very popular SOT23-3 and
TO-92 packages.
Applications
•
Power supply control loop
•
Low TC voltage reference
•
Power management applications
Features
•
Programmable precise output voltage
•
•
•
•
•
2.5V to 15V
Wide temp range: -40º to 85ºC standard
Improved stability with capacitive loads
Low TC voltage reference
Wide range of package options
RoHS compliant
Pin Configuration
Pin Descriptions
Pin Name
CATH
REF
ANODE
Function
Output and supply terminal, must be greater than 2.5V for normal operation
Input, nominally 2.495V in normal operation.
Ground and Substrate
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AQ431R
Acutechnology Semiconductor Inc.
AQ431R
Ordering Information
Device
AQ431R
AQ431R
Operating Tj
-40C˚
≤
85C˚
-40C˚
≤
85C˚
%Tol
1.5
1.5
PKG Type
TO-92-3
TO-92-3
V
OUT
2.5V
2.5V
2.5V
Wrap
BULK
T&R
T&R
Ordering Number
AQ431REX-N3-25-BUL
AQ431REX-N3-25-TRL
AQ431REX-M3-25-TRL
AQ431R
-40C˚
≤
85C˚
1.5
SOT-23-3
Note:
All parts are Lead Free and RoHS compliant.
Absolute Maximum Ratings
Stress greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. These stress ratings only, and functional operation of the device at these or any conditions beyond
those indicated under recommended Operating Conditions is not implied. Exposure to “Absolute Maximum
Rating” for extended periods may affect device reliability. Use of standard ESD handling precautions is
required.
Parameter
CATH Voltage
REF Current
CATH, ANODE Currents
Operating Junction Temperature
Lead Temperature (soldering 10 seconds)
Storage Temperature Range
ESD Rating (HBM)
Value
18
10
100
150
260
-65 to +150
3
Units
V
mA
mA
ºC
ºC
ºC
KV
Electrical Specifications
Electrical characteristics are guaranteed over the full temperature range –40ºC <Tj<85ºC unless otherwise
stated. Ambient temperature must be de-rated based upon power dissipation and package thermal
characteristics.
Symbol
V
REF
∆V
REF
Parameter
Reference Voltage
V
REF
Temperature deviation
Ratio of V
REF
Change to V
CATH
Change (Line Reg; 1/gain)
Reference input current
I
REF
Temperature Deviation
Minimum Cathode Current
Off-State Cathode Current
Dynamic Output Impedance
V
REF
=0V; V
CATH
=15V
I
CATH
=0.1 to 100mA f
≤
1.0 kHz
Conditions
25ºC; V
REF
=V
CATH
; I
CATH
=10mA
–40ºC <Tj<85ºC.
I
CATH
=10mA,
V
CATH
= V
REF
to 15V
I
CATH
=10mA
Min
2.458
Typ
2.495
8
-1
0.7
0.04
.5
.05
0.2
Max
2.532
25
-2.7
4
0.2
1
1
0.5
Units
V
mV
mV/V
µA
µA
mA
µA
Ω
∆
V
REF
∆
V
CATH
I
REF
∆I
REF
I
CATH(min)
I
CATH(OFF)
r
CATH
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Rev. 1.6 June 15, 2007
Acutechnology Semiconductor Inc.
AQ431R
Typical Performance Characteristics
Reference voltage
vs
Junction temperature
2.505
Reference input current (nA)
800
700
600
500
400
300
200
Reference input current vs junction
temperature
Reference voltage (V)
2.5
2.495
2.49
2.485
2.48
-50 -25
0
25
50
75 100 125 150
Junction temperature (degrees C)
-50 -25
0
25
50
75
100 125 150
Junction temperature (degrees C)
Cathode current vs Cathode voltage
60
40
20
0
-20
-40
-60
-80
-100
-1
0
1
Cathode voltage (V)
2
3
Typical Performance Characteristics (contd.)
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Cathode current (mA)
3
Rev. 1.6 June 15, 2007
Acutechnology Semiconductor Inc.
Off-state cathode current vs Junction
temperature
60
Delta reference voltage per delta
cathode voltage (mV/V)
Off-state cathode current (nA)
50
40
30
20
10
0
-50 -25
0
25
50
75 100 125 150
Junction temperature (degrees C)
AQ431R
Delta Reference voltage per delta cathode
voltage vs junction temperature
-0.5
-0.6
-0.7
-0.8
-0.9
-1
-1.1
-1.2
-1.3
-50 -25
0
25
50
75 100 125 150
Junction temperature (degrees C)
Open loop voltage gain vs frequency
70
60
Open loop voltage gain (dB)
50
40
30
20
10
0
-10
0.1
1
10
100
1000
10000
Frequency (KHz)
0.1
0.1
Dynamic impedance (0hms)
Dynamic impedance vs frequency
10
1
1
10
100
1000
10000
Frequency (KHz)
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Rev. 1.6 June 15, 2007
Acutechnology Semiconductor Inc.
AQ431R
Package Dimensions
SOT23-3, SOT23-4, SOT23-5, SOT23-6
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Rev. 1.6 June 15, 2007