ZR431L
ADJUSTABLE PRECISION SHUNT REGULATOR
SUMMARY
DESCRIPTION
The ZR431L is a three terminal adjustable shunt regulator offering excellent
temperature stability and output current handling capability up to 25mA. The
output voltage may be set to any chosen voltage between 1.24 and 10 volts
by selection of two external divider resistors.
The devices can be used as a replacement for zener diodes in many
applications requiring an improvement in zener performance.
The ZR431L is particularly used in the feedback control loop of switch mode
power supplies. In this application the device 1.24 volt reference enables the
generation of low voltage supplies, typically 3.3. volts or 3 volts.
SOT23
FEATURES
•
2.5% and 1% tolerance
•
Max. temperature coefficient 50 ppm/°C
•
Temperature compensated for operation over the full temperature range
•
100 A to 25mA current sink capability
•
Surface mount SOT23 package
•
TO92 package
TO92
APPLICATIONS
•
•
•
•
•
Switch mode power supplies
Shunt regulator
Series regulator
Voltage monitor
Over voltage / under voltage protection
SOT23
ORDERING INFORMATION
DEVICE
ZR431LF01TA
ZR431LF02TA
ZR431LC01STOB
ZR431LC02STOB
ZR431LC01L
ZR431LC02L
PACK
SOT23
SOT23
TO92
TO92
TO92
TO92
TOL %
1
2.5
1
2.5
1
2.5
LOOSE
LOOSE
REEL
SIZE
7”
7”
QUANTITY
PER REEL
3000
3000
1500
1500
PART MARK
43M
43L
ZR431L01
ZR431L02
ZR431L01
ZR431L02
Top View
TO92
Underside
View
ISSUE 2 - AUGUST 2003
1
SEMICONDUCTORS
ZR431L
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Cathode Voltage
Cathode Current
Operating Temperature
Storage Temperature
T
OMP
T
STG
SYMBOL
V
Z
LIMIT
10
50
-40 to 85
-55 to 125
UNIT
V
mA
°C
°C
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Cathode Voltage
Cathode Current
MIN.
V
REF
100 A
MAX.
10V
25mA
POWER DISSIPATION
(at T
amb
= 25°C unless otherwise stated)
PACKAGE
SOT23
TO92
VALUE
330
600
UNIT
mW
mW
ISSUE 2 - AUGUST 2003
SEMICONDUCTORS
2
ZR431L
BLOCK DIAGRAM
Deviation of reference input voltage, V
dev
, is defined as the
maximum variation of the reference input voltage over the full
temperature range.
The average temperature coefficient of the reference input
voltage, V
ref
is defined as:
V
ref
(
ppm
/
C
)
=
V
dev
x
1000000
V
ref
(
T
1
−
T
2)
The dynamic output impedance, R
z
, is defined as:
R
Z
=
∆
V
Z
∆
l
Z
When the device is programmed with two external resistors,
R1 and R2, (fig 2), the dynamic output impedance of the
overall circuit, R’, is defined as:
R
'
=
R
Z
(1
+
R
1
)
R
2
ISSUE 2 - AUGUST 2003
3
SEMICONDUCTORS
ZR431L
ELECTRICAL CHARACTERISTICS
(at T
amb
= 25°C unless otherwise stated)
PARAMETER
Reference Voltage
2.5%
1.0%
SYMBOL
V
ref
Vref
V
dev
∆
V
ref
∆
V
Z
I
ref
∆
I
ref
0.02
MIN.
1.209
1.228
TYP.
1.24
1.24
4.0
0.5
MAX.
1.271
1.252
8.0
2.0
UNIT CONDITIONS
V
V
mV
I
L
= 10mA (Fig1), V
Z
= V
ref
I
L
= 10mA, V
Z
= V
ref
T
a
= full range (Fig 1)
Deviation of Reference Input
Voltage over Temperature
Ratio of the change in Reference
Voltage to the change in Cathode
Voltage
Reference Input Current
Deviation of Reference Input
Current over Temperature
Minimum Cathode Current for
Regulation
Off-state Current
Dynamic Output Impedance
mV/V V from V
Z
ref
to 10V
I
Z
= 10mA (Fig2)
A
A
R1 = 10k, R2 = O/C,
l
L
= 10mA (fig2)
R1 = 10k, R2 = O/C,
I
L
= 10mA T
a
= full range
(Fig2)
0.11
0.02
0.4
0.2
I
Zmin
I
Zoff
R
Z
30
10
0.25
100
30
2
A
A
V
Z
= 10V, V
ref
= 0V (Fig3)
V Z = V ref (Fig1), f = 0Hz,
I L = 10mA
DC TEST CIRCUITS
Fig 1 - Test Circuit for VZ = Vref
Fig 2 - Test Circuit for VZ > Vref
Fig 3 - Test Circuit for Off State
current
ISSUE 2 - AUGUST 2003
SEMICONDUCTORS
4
ZR431L
TYPICAL CHARACTERISTICS
ISSUE 2 - AUGUST 2003
5
SEMICONDUCTORS
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