Zetex ZR431LC01, ZR431LC02, ZR431LF01, ZR431LF02 Datasheet
ADJUSTABLE PRECISION
ZENER SHUNT REGULATOR
Issue 1 - NOVEMBER 1998
ZR431L
DEVICE 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.
SCHEMATIC DIAGRAM
V
ref
FEATURES
Surface mount SOT23 package
•
TO92 package
•
2.5% and 1% tolerance
•
Maximum temperature coefficient 50
•
ppm/°C
Temperature compensated for
•
operation over the full temperature
range
Programmable output voltage
•
100µA to 25mA current sink capability
•
Low output noise
•
APPLICATIONS
Shunt regulator
•
Series regulator
•
Voltage monitor
•
Over voltage/ under voltage protection
•
Switch mode power supplies
•
V
Z
G
nd
ZR431L
ABSOLUTE MAXIMUM RATING
Cathode Voltage (VZ) 10V
Cathode Current 50mA
Operating Temperature -40 to 85°C
Power Dissipation (T
=150°C)
T
jmax
SOT23 330mW
TO92 600mW
amb
=25°C,
Storage Temperature -55 to 125°C
Recommended Operating Conditions
Min Max
Cathode Voltage V
REF
10V
Cathode Current 100µA25mA
ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated):T
VALUE
PARAMETER SYMBOL
Reference Voltage 2.5%
V
1.0%
Deviation of Reference
V
MIN TYP MAX
1.209
ref
1.228
dev
1.24
1.24
4.0 8.0 mV IL=10mA, VZ=V
Input Voltage over
Temperature
Ratio of the change in
Reference Voltage to the
Change in Cathode
V
∆
ref
∆
V
Z
0.5 2.0 mV/V VZ from V
Voltage
I
ref
0.02 0.11 0.4
0.02 0.2
Reference Input Current I
Deviation of Reference
ref
∆
Input Current over
Temperature
Minimum Cathode
I
Zmin
30 100
Current for Regulation
Off-state Current I
Dynamic Output
R
Zoff
Z
10 30
0.25 2
Impedance
Deviation of reference input voltage, V
reference input voltage over the full temperature range.
Vmax
Vmin
Vdev = Vmax - Vmin
T1 T2
Temperature
is defined as the maximum variation of the
dev,
The average temperature coefficient of the
reference input voltage, V
V
(
ref
The dynamic output impedance, Rz, is defined
as:
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:
UNITS CONDITIONS
1.271
VIL=10mA (Fig1), VZ=V
1.252
Ta=full range (Fig1)
=10mA (Fig2)
I
Z
R1=10k, R2=O/C, lL=10mA (Fig2)
µA
R1=10k, R2=O/C, IL=10mA
µA
=full range (Fig2)
T
a
µA
VZ=10V, V
µA
VZ=V
ppm
⁄
Ω
°C)=
R
R’=R
V
=
Z
z
I
=10mA
L
x 1000000
dev
V
(T1−T2)
ref
V
∆
Z
∆
I
Z
R
1
(1+
R
2
ref
)
to 10V
ref
=0V (Fig3)
ref
(Fig1), f=0Hz,
is defined as:
ref
ref
amb
=25°C
ref
CONNECTION DIAGRAMS
ZR431L
SOT23 Package Suffix – F
Top View
ORDERING INFORMATION
Part
Number
ZR431LF02 SOT23 2.5 43L
ZR431LF01 SOT23 1 43M
ZR431LC02 TO92 2.5 ZR431L02
ZR431LC01 TO92 1 ZR431L01
Package Tol%Part Mark
TO92 Package Suffix – C
Bottom View
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