Bay Linear
Inspire the Linear Power
1.24V Adjustable Shunt Regulator
Description
The B431L is a three terminal adjustable shunt regulator with
thermal stability of 50ppm/°C. The output voltage can be
adjusted to any value from 1.24V (V
REF
) to 16V with two
external resistors. These devices have a typical output
impedance of 0.05Ω. Active output circuitry provides a very
sharp turn-on characteristics and making the device excellent
replacement for zener diodes in many applications. The B431L
is an ideal voltage reference in an isolated feedback circuit for
3.0V switch mode power supplies
The B431L shunt regulator is available with three voltage
tolerances (0.5%, 1.0% and 2.0%) and three package options
(SOT-23-3, TO-92, 8SOIC). This allows the designer the
opportunity to select the optimum combination of cost and
performance for their application.
B431L
Features
•
•
•
•
•
Low voltage operation (down to 1.24V)
Wide operating current……80µA to 100mA
Trimmed bandgap design………….. ± 0.5%
Low Dynamic Output Impedance…....0.05Ω
Ω
Wide temperature range…... -40°C to +85°C
°
°
Available in ….….SOT-23-3, TO-92 , 8SOIC
Pin-to-Pin Replacement …………….SC431L
•
•
Applications
•
•
•
•
•
•
Switching Power Supplies
Adjustable Power Supplies
Linear Regulators
Battery Powered Equipment
Monitors, TV, VCR
Instrumentation
Pin Connection
Ordering Information
Package
TO-92
SO-8
SOT-23
0.5%
B431LAZ
B431LAM
B431LAK3
Tolerance
1%
B431LBZ
B431LBM
B431LBK3
2%
B431LCZ
B431LCM
B431LCK3
SOT-23-3 (K3)
TO-92 (Z)
1
2
3
Anode
BAY
Ref
Anode
Bottom View
Cathode
Ref
Cathode
Top View
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
Absolute Maximum Rating
Parameter
Cathode Voltage
Continuous Cathode Current
Reference Input Current Range
Power Dissipation at T
A
- 25°C
SOT-23-3
S0-8
TO-92
Thermal Resistance
SOT-23-3
S0-8
TO-92
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (Soldering) 10 seconds
ESD Rating (Human Body Model)
Recommended Operating Conditions
Symbol
V
z
I
z
P
D
Maximum
20
100
3
0.37
0.75
0.95
336
175
132
-40 to +150
-65 to +150
300
2
Units
V
mA
mA
W
O
JA
T
J
T
STG
T
LEAD
T
ESD
°C/W
°C
°C
°C
kV
Min
Cathode Voltage, Vz
Cathode Current, Iz
V
REF
80µA
Max
16
100
Symbol
V
mA
Electrical Characteristics
Unless specified: T
٨
= 25°C
. Values in bold apply over full operating ambient temperature.
B431LA 0.5%
Parameter
Reference Voltage
V
REF
Temp Deviation
Ratio of Change in
V
REF
To Change in V
Z
Reference Input
Current
I
REF
Temperature
Deviation
Off-State Cathode
Current
Min Operating
Current
Dynamic Impedance
Symbol
V
REF
V
DEV
Δ
V
REF
ΔV
Z
I
REF
I
REF(DEV)
I
Z (OFF)
Condition
V
Z
= V
REF1
I
Z
= 10mA
(1)
V
Z
= V
REF1,
I
Z
= 10mA
(1)
I
A
=full range
I
Z
= 10mA,ΔV
Z
= 16V to V
Ref
(2)
R1 = 10kΩ, R2 =
∞,
I
Z
= 10mA
(2)
R1 = 10kΩ, R2 =
∞,
I
Z
= 10mA
(2)
V
REF
= 0V, V
Z
=16V
V
REF
= 0V, V
Z
=16V
(3)
V
Z
= V
REF(1)
V
KA
=V
ref
,
I
K
=100µA to 100mA, f≤1kHA
(3)
Min
1.234
1.222
Typ
1.240
10
-2.7
0.15
0.1
0.125
0.135
20
0.05
Max
1.246
1.258
25
-1.0
0.5
0.4
0.150
Units
V
mV
mV/V
µA
µA
µA
0.150
80
0.15
µA
Ω
I
Z(MIN)
Z
KA
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
Electrical Characteristics
Unless specified: T
٨
= 25°C
. Values in bold apply over full operating ambient temperature.
B431LB 1%
Parameter
Reference Voltage
V
REF
Temp Deviation
Ratio of Change in
V
REF
To Change in V
Z
Reference Input
Current
I
REF
Temperature
Deviation
Off-State Cathode
Current
Min Operating
Current
Dynamic Impedance
Symbol
V
REF
V
DEV
Δ
V
REF
ΔV
Z
I
REF
I
REF(DEV)
I
Z (OFF)
Condition
V
Z
= V
REF1
I
Z
= 10mA
(1)
V
Z
= V
REF1,
I
Z
= 10mA
(1)
I
A
=full range
I
Z
= 10mA,ΔV
Z
= 16V to V
Ref
(2)
R1 = 10kΩ, R2 =
∞,
I
Z
= 10mA
(2)
R1 = 10kΩ, R2 =
∞,
I
Z
= 10mA
(2)
V
REF
= 0V, V
Z
=16V
(3)
V
REF
= 0V, V
Z
=16V
I
Z(MIN)
Z
KA
V
Z
= V
REF(1)
V
KA
=V
ref
,
I
K
=100µA to 100mA, f≤1kHA
(3)
Min
1.228
1.215
Typ
1.240
10
-1.0
0.15
0.1
0.125
0.135
20
0.05
Max
1.252
1.265
25
-2.7
0.5
0.4
0.150
Units
V
mV
mV/V
µA
µA
µA
0.150
80
0.15
µA
Ω
Electrical Characteristics
Unless specified: T
٨
= 25°C
. Values in bold apply over full operating ambient temperature.
B431LC 2%
Parameter
Reference Voltage
V
REF
Temp Deviation
Ratio of Change in
V
REF
To Change in V
Z
Reference Input
Current
I
REF
Temperature
Deviation
Off-State Cathode
Current
Min Operating
Current
Dynamic Impedance
Symbol
V
REF
V
DEV
Δ
V
REF
ΔV
Z
I
REF
I
REF(DEV)
I
Z (OFF)
Condition
V
Z
= V
REF1
I
Z
= 10mA
(1)
V
Z
= V
REF1,
I
Z
= 10mA
(1)
I
A
=full range
I
Z
= 10mA,ΔV
Z
= 16V to V
Ref
(2)
R1 = 10kΩ, R2 =
∞,
I
Z
= 10mA
(2)
R1 = 10kΩ, R2 =
∞,
I
Z
= 10mA
(2)
V
REF
= 0V, V
Z
=16V
(3)
V
REF
= 0V, V
Z
=16V
I
Z(MIN)
Z
KA
V
Z
= V
REF(1)
V
KA
=V
ref
,
I
K
=100µA to 100mA, f≤1kHA
(3)
Min
1.215
1.200
Typ
1.240
10
-1.0
0.15
0.1
0.125
0.135
20
0.05
Max
1.265
1.280
35
-2.7
0.5
0.4
0.150
Units
V
mV
mV/V
µA
µA
µA
0.150
80
0.15
µA
Ω
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com