WSL
432
Adjustable Precision Shunt Regulator
Features
Precise Reference Voltage to 1.240V
Guaranteed 1% and 1.5% Reference Voltage
Tolerance
Sink Current Capability, 0.1mA to 20mA
Quick
Turn-on
Adjustable Output Voltage, Vo
= V
ref
to 6V
Low Operational Cathode Current, 42A
Typical
0.1 Typical Output Impedance
TO-92 and SOT-23 Package
Applications
Linear Regulators
Adjustable Power Supply
Switching Power Supply
General Description
The WSL432 is a 3 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 6V with two external resistors
(see Figure 2).
When used with a photo-coupler, the WSL432 is
an ideal voltage reference in isolated feedback
circuits for 1.24V to 6V switching-mode power
supplies.
This device has a typical output impedance of
0.1. Active output circuitry provides a very
sharp turn-on characteristic, making the
WSL432 excellent replacements for zener diodes
in many applications, including on-board
regulation and adjustable power supplies.
TO-92
SOT-23 (Top View)
Winson reserves the right to make changes to improve reliability or manufacturability.
Winson, Jan. 2000 (Rev. A)
WSL
432
Ordering Information
WSL432-XP
Elect. Grade
3: 1% Reference Voltage Tolerance
Elect. Grade 5: 1.5% Reference Voltage Tolerance
Package Code
Package Code
A: TO-92
C: SOT-23
Symbol
REF
ANODE CATHODE
Functional Diagram
Winson reserves the right to make changes to improve reliability or manufacturability.
Winson, Jan. 2000 (Rev. A)
WSL
432
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
V
KA
Cathode voltage
7
V
I
K
Continuous cathode current range
30
mA
I
ref
Reference current range
3
mA
T
A
Ambient temperature range
0 to 85
C
T
J
Junction temperature range
0 to 125
C
T
STG
Storage Temperature Range
-65 to 150
C
T
SO
Lead temperature range, T
s
(Soldering,
10sec)
260
C
Electrical Characteristics T
A
= 25C (unless otherwise noted)
WSL432
Symbol Parameter
Test
Conditions
Min. Typ. Max.
Unit
WSL432
(1%)
1.228 1.24 1.252
V
V
ref
V
KA
=Vref, I
K
=10mA.
WSL432
(1.5%)
1.222 1.24 1.258
V
V
ref
/T
Reference Voltage Drift over
Temp. range
T
A
=0 to 85C
*1
, I
k
=10mA.
4
20
mV
V
ref
/V
KA
Voltage Ration
(open loop gain)
I
K
=10 mA, V
KA
=Vref to 6V
*2
0.8 2.7 mV/
V
I
ref
Reference Current
I
K
=10mA,
R
1
=10K, R
2
=open
*2
0.15
0.5
A
I
ref
(dev)
I
ref deviation
I
K
=10mA,
R
1
=10K, R
2
=open
*2
0.1
0.4
uA
I
ref
/T
Reference Current Drift
I
K
=10 mA,
R
1
=10K, R
2
=open, TA=0 to
85C
*2
0.4
1.2
A
I
K(min)
Min. Cathode Current
V
KA
=Vref
*1
42
80
uA
I
K(off)
Off-state Cathode Current
V
KA
=6V, Vref=0V
*3
0.001
0.1
A
z
KA
Dynamic Impedance
V
KA
=Vref, IK=0.1 mA to
20mA, f=1k Hz*1
0.1
0.4
Notes:
*1
: use Figure 1
*2
: use Figure 2
*3
: use Figure 3
Winson reserves the right to make changes to improve reliability or manufacturability.
Winson, Jan. 2000 (Rev. A)
WSL
432
Test figures
Figure 1. Test Circuit for V
KA
=V
REF
Figure 2. Test Circuit for V
KA
<V
REF
,
V
O
=V
KA
=V
REF
V
O
=V
KA
=V
REF
(1+R
1
/R
2
)+I
REF
R
1
Figure 3. Test Circuit for I
k(off)
Winson reserves the right to make changes to improve reliability or manufacturability.
Winson, Jan. 2000 (Rev. A)
WSL
432
TYPICAL CHARACTERISTICS
Vref. vs Free-Air Temperature
1.22
1.23
1.24
1.25
1.26
0
50
100
150
Vref.(V)
1.250V
1.241V
1.277V
Iref. vs Free-Air Temperature
0
0.05
0.1
0.15
0.2
0.25
0
20
40
60
80
100
120
Ire
f
.(uA)
Ratio of Delta Vref to Delta Vk vs Temperature
0
0.0005
0.001
0.0015
0
20
40
60
80
100
120
dVr
e
f
/
dVk(
mV/V)
Ik(off) vs. Free-Air Temperature
-0.05
0
0.05
0.1
0.15
0
20
40
60
80
100
120
Ik(off)
-
(uA)
Cathode Current vs Cathode Voltage
-15
-10
-5
0
5
10
-1
-0.5
0
0.5
1
1.5
Vka(V)
Ik
(m
A)
Winson reserves the right to make changes to improve reliability or manufacturability.
Winson, Jan. 2000 (Rev. A)
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