ETC1 B431LAZ 1.24v adjustable shunt regulator Datasheet

Bay Linear
Inspire the Linear Power
B431L
1.24V Adjustable Shunt Regulator
Description
Features
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 (VREF) 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.
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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
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Applications
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Pin Connection
Switching Power Supplies
Adjustable Power Supplies
Linear Regulators
Battery Powered Equipment
Monitors, TV, VCR
Instrumentation
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
Anode
3
BAY
Ref
Anode
Bottom View
Bay Linear, Inc
Cathode
Ref
Cathode
Top View
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 TA - 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)
Symbol
Maximum
Units
Vz
Iz
20
100
3
V
mA
mA
PD
0.37
0.75
0.95
W
OJA
336
175
132
-40 to +150
-65 to +150
300
2
°C/W
TJ
TSTG
TLEAD
TESD
°C
°C
°C
kV
Recommended Operating Conditions
Cathode Voltage, Vz
Cathode Current, Iz
Min
Max
Symbol
VREF
80µA
16
100
V
mA
Electrical Characteristics
Unless specified: T٨ = 25°C. Values in bold apply over full operating ambient temperature.
B431LA 0.5%
Parameter
Reference Voltage
Symbol
VREF
Condition
VZ = VREF1 IZ = 10mA(1)
Min
1.234
Typ
1.240
1.222
VREF Temp Deviation
Ratio of Change in
VREF To Change in VZ
Reference Input
Current
IREF Temperature
Deviation
Off-State Cathode
Current
Δ VREF
ΔVZ
IREF
IREF(DEV)
IZ (OFF)
Min Operating
Current
Dynamic Impedance
Bay Linear, Inc
VDEV
(1)
VZ = VREF1, IZ = 10mA
IA=full range
IZ = 10mA,ΔVZ = 16V to VRef
(2)
R1 = 10kΩ, R2 = ∞,
IZ = 10mA(2)
R1 = 10kΩ, R2 = ∞,
IZ = 10mA(2)
Max
1.246
Units
V
1.258
10
25
mV
-2.7
-1.0
mV/V
0.15
0.5
µA
0.1
0.4
µA
VREF = 0V, VZ =16V(3)
VREF = 0V, VZ =16V(3)
0.125
0.150
0.135
0.150
IZ(MIN)
VZ = VREF(1)
20
80
µA
ZKA
VKA=Vref,
IK=100µA to 100mA, f≤1kHA
0.05
0.15
Ω
µA
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
Electrical Characteristics
Unless specified: T٨ = 25°C. Values in bold apply over full operating ambient temperature.
B431LB 1%
Parameter
Reference Voltage
Symbol
VREF
Condition
VZ = VREF1 IZ = 10mA(1)
Min
1.228
Typ
1.240
1.215
VREF Temp Deviation
Ratio of Change in
VREF To Change in VZ
Reference Input
Current
IREF Temperature
Deviation
Off-State Cathode
Current
VDEV
Δ VREF
ΔVZ
Units
V
1.265
10
25
mV
-1.0
-2.7
mV/V
0.15
0.5
µA
µA
R1 = 10kΩ, R2 = ∞,
IZ = 10mA(2)
R1 = 10kΩ, R2 = ∞,
IZ = 10mA(2)
VREF = 0V, VZ =16V(3)
0.1
0.4
0.125
0.150
VREF = 0V, VZ =16V(3)
0.135
0.150
IZ(MIN)
VZ = VREF(1)
20
80
µA
ZKA
VKA=Vref,
IK=100µA to 100mA, f≤1kHA
0.05
0.15
Ω
IREF
IREF(DEV)
IZ (OFF)
Min Operating
Current
Dynamic Impedance
VZ = VREF1, IZ = 10mA(1)
IA=full range
IZ = 10mA,ΔVZ = 16V to VRef
(2)
Max
1.252
µA
Electrical Characteristics
Unless specified: T٨ = 25°C. Values in bold apply over full operating ambient temperature.
B431LC 2%
Parameter
Reference Voltage
Symbol
VREF
Condition
VZ = VREF1 IZ = 10mA(1)
Min
1.215
Typ
1.240
1.200
VREF Temp Deviation
Ratio of Change in
VREF To Change in VZ
Reference Input
Current
IREF Temperature
Deviation
Off-State Cathode
Current
Δ VREF
ΔVZ
VZ = VREF1, IZ = 10mA
IA=full range
IZ = 10mA,ΔVZ = 16V to VRef
(2)
Units
V
1.280
10
35
mV
-1.0
-2.7
mV/V
0.15
0.5
µA
µA
R1 = 10kΩ, R2 = ∞,
IZ = 10mA(2)
R1 = 10kΩ, R2 = ∞,
IZ = 10mA(2)
VREF = 0V, VZ =16V(3)
0.1
0.4
0.125
0.150
VREF = 0V, VZ =16V(3)
0.135
0.150
IZ(MIN)
VZ = VREF(1)
20
80
µA
ZKA
VKA=Vref,
IK=100µA to 100mA, f≤1kHA
0.05
0.15
Ω
IREF
IREF(DEV)
IZ (OFF)
Min Operating
Current
Dynamic Impedance
Bay Linear, Inc
VDEV
(1)
Max
1.265
µA
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
Test Circuit: Small-Signal Gain & Phase
43
1
Test Circuit: Stability
431
L
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
Application Notes:
Stability: Selection of Load Capacitor
Selection of load capacitor for when B431L is used as a
shunt regulator, two options for selection of CL 1) No
load capacitance across the device, decouple at the load
2) Large capacitance across the device, optional
decoupling at the load.
The reason for this is that B431L exhibits instability
with capacitances in the range of 10nF to 1µF (approx.)
at light cathode currents (up to 3mA typical). The
device is less stable the lower the cathode voltage has
been set for. Therefore while the device will be
perfectly stable operating at a cathode current of 10mA
with a 0.1µF capacitor across it, it will oscillate
transiently during start-up as the cathode current passes
through the instability region. Selecting a very low (or
preferably, no) capacitance, or alternatively a high
capacitance such as 10µF will avoid this issue
altogether. Since the user anyway, the most cost
effective method is to use no capacitance at all directly
across the device. PCB trace/via resistance and
inductance prevent the local load decoupling from
causing the oscillation during the transient start-up
phase.
Note: if the B431L is located right at the load, so the
load decoupling capacitor is directly across it, then this
capacitor will have to be ≤1nF or ≥ 10µF
B431
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
Test Circuits:
Application Circuit:
+3.3V
0.1µF
470µF
PHD 3055E
+12V
500Ω
2.7V
140Ω
0.1µF
0.1µF
0.1µF
B431L
120Ω
INTEL
I 740
1000µF
*If the output voltage has noise, then please add a 0.1µF in between drain and gate of power MOSFET to
reduce the noise.
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B431L
SOT-23
0.015 - 0.018
(0.381 - 0.457)
0.047 - 0.055 0.083 - 0.098
(1.194 - 1.397) (2.108 - 2.489)
0.035 - 0.040
(0.889 - 1.016)
0.020 - 0.024
(0.508 - 0.610)
0.070 - 0.080
(1.778 - 2.032)
0.110 - 0.120
(2.794 - 3.048)
0.001 - 0.004
(0.025 - 0.102)
0.003 - 0.005
(0.076 - 0.127)
0.030 - 0.041
(0.762 - 1.041)
0.018 - 0.024
(0.457 - 0.610)
Advance Information- These data sheets contain descriptions of products that are in development. The specifications are based on the engineering calculations,
computer simulations and/ or initial prototype evaluation.
Preliminary Information- These data sheets contain minimum and maximum specifications that are based on the initial device characterizations. These limits are
subject to change upon the completion of the full characterization over the specified temperature and supply voltage ranges.
The application circuit examples are only to explain the representative applications of the devices and are not intended to guarantee any circuit
design or permit any industrial property right to other rights to execute. Bay Linear takes no responsibility for any problems related to any
industrial property right resulting from the use of the contents shown in the data book. Typical parameters can and do vary in different
applications. Customer’s technical experts must validate all operating parameters including “ Typical” for each customer application.
LIFE SUPPORT AND NUCLEAR POLICY
Bay Linear products are not authorized for and should not be used within life support systems which are intended for surgical
implants into the body to support or sustain life, in aircraft, space equipment, submarine, or nuclear facility applications without
the specific written consent of Bay Linear President.
Bay Linear, Inc
2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
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