GM431
2.5V ADJUSTABLE
SHUNT REGULATOR
Description
The GM431is a three terminal adjustable shunt
regulator with thermal stability guaranteed over
temperature. The output voltage can be adjusted
to any value between 2.5V (V
REF
) and 18V by
using two external resistors. The GM431 has a
typical dynamic output impedance of 0.2 . Active
output circuitry provides a very unique turn on
characteristic, making the GM431an excellent
replacement for zener diodes in many
applications such as on board regulation and
adjustable power supplies. The GM431 is an
ideal voltage reference for 3.0 to 3.3V switching
power supplies.
The GM431 shunt regulator is available with 3
voltage tolerances 0.5%, 1.0% and 2.0% over
full temperature range and four package options
(SOT-23, TO-92, SOT-89 and SO-8).
Features
Sink Current Capability 1mA to 100mA
Low dynamic out put impedance, 0.2
typ.
Low output noise
0.5%, 1% or 2% reference voltage
tolerance
Alternate for TL431, LM431 & AS431
Temperature range
-40°C to + 125°C
Available in SOT-23, TO-92, SOT-89 and
Sop- 8 packages
Application
Switching power supplies
Linear regulator
Adjustable supplies
Battery-operated computers
Computer disk drives
Instrumentation
Logic Symbol
Block Diagram
Cathode
Reference
Anode
Cathode
Reference
V
REF
Anode
www.gammamicro.com.tw
GM431
V1.07
1
GM431
2.5V ADJUSTABLE
SHUNT REGULATORS
Marking Information and Pin Configurations (Top View)
SOT23
TO92
SOT89
7. Anode
8. Ref
SO8
6. Anode
5. NC
Anode
2
AAXYW
1
Re
f
3
Cathode
431G
AYWW
431G
AYWW
Ref 1
3 Cathode
2
Anode
1. Cathode
2. Anode
GM431G
AYWW
Ref 1
2
3 Cathod
e
Anode
(GM431)
4. NC
3. Anode
Anode
2
RAXYW
1
Cathode
3
Ref
(GM431R)
AAX: Marking Code (see table below)
RAX: Marking Code (see table below)
G: Grade Code (A: 0.5%, B: 1.0%, C: 2.0%)
A: Assembly/Test Site Code
Y: Year
W: Week code
WW: Week
GM431
V1.07
2
GM431
2.5V ADJUSTABLE
SHUNT REGULATOR
Ordering Information
Ordering Number
GM431AT92B
GM431AT92RL
GM431AST23R
GM431RAST23R
GM431AS8T
GM431AS8R
GM431AST89R
GM431BT92B
GM431BT92RL
GM431BST23R
GM431RBST23R
GM431BS8T
GM431BS8R
GM431BST89R
GM431CT92B
GM431CT92RL
GM431CST23R
GM431RCST23R
GM431CS8T
GM431CS8R
GM431AST89R
Precision Device Code
0.5%
0.5%
0.5%
0.5%
0.5%
0.5%
0.5%
1.0%
1.0%
1.0%
1.0%
1.0%
1.0%
1.0%
2.0%
2.0%
2.0%
2.0%
2.0%
2.0%
2.0%
AAC
RAC
C
C
C
AAB
RAB
B
B
B
A
C
AAA
RAA
A
A
A
B
B
Grade
A
A
Package
TO-92
TO-92
SOT-23
SOT-23
SO-8
SO-8
SOT-89
TO-92
TO-92
SOT-23
SOT-23
SO-8
SO-8
SOT-89
TO-92
TO-92
SOT-23
SOT-23
SO-8
SO-8
SOT-89
Shipping
1,000 Units/ESD Bag
2,000 Units/Ammo Pack (Tape)
3,000 Units/Tape & Reel
3,000 Units/Tape & Reel
100 Units/Tube
2,500 Units/Tape & Reel
1,000 Units/Tape & Reel
1,000 Units/ESD Bag
2,000 Units/Ammo Pack (Tape)
3,000 Units/Tape & Reel
3,000 Units/Tape & Reel
100 Units/Tube
2,500 Units/Tape & Reel
1,000 Units/Tape & Reel
1,000 Units/ESD Bag
2,000 Units/Ammo Pack (Tape)
3,000 Units/Tape & Reel
3,000 Units/Tape & Reel
100 Units/Tube
2,500 Units/Tape & Reel
1,000 Units/Tape & Reel
GM431
V1.07
3
GM431
2.5V ADJUSTABLE
SHUNT REGULATORS
Absolute Maximum Ratings
PARAMETER
Cathode Voltage
Continuous Cathode Current Range
Reference Input Current Range
Power Dissipation at T
A
= 25°C
SOT-23
TO-92
SOT-89
SO-8
Package Thermal Resistance
SOT-23
TO-92
SOT-89
SO-8
Operating Ambient Temperature Range
Storage Temperature
Lead Temperature (soldering 10 sec.)
SYMBOL
V
KA
I
K
I
REF
RATINGS
20
-100 to 150
-50µA to 10mA
0.23
0.78
0.8
0.6
336
132
132
163
-40 - 125
- 65 to 150
260
UNITS
V
mA
P
D
W
θ
JA
T
A
°C/W
°C
°C
°C
Recommended Operating Conditions
PARAMETER
Cathode Voltage
Cathode Current
SYMBOL
V
KA
I
K
Min
V
REF
10
Max
18
100
UNITS
V
mA
Equivalent Schematics
Cathode
800
800
20pF
Reference
3.28K
4K
10k
GM431
V1.07
2.4K
7.2K
20pF
1K
Anode
4
GM431
2.5V ADJUSTABLE
SHUNT REGULATOR
Electrical Characteristics
(T
A
= 25°C unless otherwise specified)
Parameter
GM431A
Reference
Voltage
GM431B
GM431C
V
REF
Deviation over
Temperature
Ratio of change in V
REF
to change in V
KA
Reference Input
Current
I
REF
Deviation over
Temperature
Minimum Cathode
Current
Off-state cathode
Current
Dynamic Impedance
V
REF(DEV)
∆V
REF
/∆V
KA
I
REF
V
REF(DEV)
I
K(MIN)
I
K(OFF)
|Z
KA
|
V
KA
= V
REF
, I
K
= 10mA,
Full Range
Test circuit 1
I
K
= 10mA
∆V
KA
= 10V to V
REF
∆V
KA
= 18V to 10V
-2.7
-2
V
REF
V
KA
= V
REF
, I
K
= 10mA,
Test circuit 1
Symbol
Condition
Min
2.488
2.475
2.450
Typ
2.500
2.500
2.500
4
-1.0
-0.4
1.3
0.4
0.4
0.1
0.2
Max
2.513
2.525
2.550
17
Unit
mV
mV
µA
I
K
= 10mA, R1 = 10K, R2 =
∞
Test circuit 2
I
K
= 10mA, R1 = 10K, R2 =
∞
Full range, Test circuit 2
V
KA
= V
REF
Test
circuit 1
V
KA
= 18V, V
REF
= 0V
Test
circuit 3
V
KA
= V
REF
, I
K
= 1mA to 10mA,
f
≤1kHz,
Test circuit 1
4
1.2
1.0
1
0.5
µA
µA
mA
µA
Ω
Test Circuits
V
IN
V
KA
I
K
V
IN
V
KA
V
IN
V
KA
I
K(OFF)
R1
I
REF
V
REF
V
REF
I
K
V
REF
R2
GM431
V1.07
5
Test Circuit 1
V
KA
= V
REF
Test Circuit 2
V
KA
>
V
REF
Test Circuit 3
Off-State
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