A Product Line of
Diodes Incorporated
ZHT431
Adjustable Precision Zener Shunt Regulator
Description
The ZHT431 is a three terminal adjustable shunt
regulator offering excellent temperature stability
and output current handling capability up to
100mA. The device offers extended operating
temperature range working from -55 to +125°C.
The output voltage may be set to any chosen
voltage between 2.5 and 20 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.
Features
Applications
•
Surface mount SOT223 and SOT23 packages
•
Series and shunt regulator
•
0.5%, 1% and 2% tolerance
•
Voltage monitor
•
Maximum temperature coefficient 67 ppm/°C
•
Over voltage / under voltage protection
•
Temperature compensated for operation over
the full temperature range
•
Switch mode power supplies
•
Programmable output voltage
Pinout Information
•
50mA to 100mA current sink capability
•
Low output noise
•
Available in “Green” Molding Compound
(No Br, Sb) denoted by -7
•
Wide temperature range -55 to +125°C
VZ
VREF
GND
GND
GND
VZ
SOT223
Pinout - Top view
VREF
SOT23
Pinout - Top view
Ordering Information
Order Reference
ZHT431C01L
ZHT431C01STOB
ZHT431C01STZ
ZHT431C02L
ZHT431C02STOB
ZHT431C02STZ
ZHT431F01TA
ZHT431F01-7
ZHT431FMTA
ZHT431F02TA
ZHT431G01TA
ZHT431G02TA
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Tolerance Package Part mark Status
(%)
1
TO92 ZHT43101 Obsolete
1
TO92 ZHT43101 Obsolete
1
TO92 ZHT43101 Obsolete
2
TO92 ZHT43102 Obsolete
2
TO92 ZHT43102 Obsolete
2
TO92 ZHT43102 Obsolete
1
SOT23
43C
Active
1
SOT23
43C
Active
0.5
SOT23
43P
Active
2
SOT23
43D
Active
1
SOT223 ZHT43101 Active
2
SOT223 ZHT43102 Active
1
Reel size
(inches)
Loose
12.5
Concertina
Loose
12.5
Concertina
7
7
7
7
7
7
Quantity
per reel
4000
1500
1500
4000
1500
1500
3000
3000
3000
3000
1000
1000
Tape
width
8mm
8mm
8mm
8mm
12mm
12mm
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ZHT431
Schematic Diagram
Absolute Maximum Rating
Cathode voltage (VZ)
20V
Power dissipation (Tamb=25°C)
Cathode current
150mA
(Tjmax = 150°C)
Operating temperature
-55 to 125°C
SOT23
330mW
Storage temperature
-55 to 150°C
SOT223
2W
Recommended Operating Conditions
Min.
Max.
Cathode voltage
VREF
20V
Cathode current
50µA
100mA
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ZHT431
Electrical Characteristics Test Conditions (unless otherwise stated):Tamb=25°C
Symbol Parameter
VREF
Value
Units Conditions
Min.
Typ.
Max.
2.45
2.50
2.55
V
1% 2.475
2.50
2.525
V
0.5% 2.4875
Reference voltage
2%
IL=10mA (Fig.1),
VZ=VREF
2.50
2.5125
V
VDEV
Deviation of reference input
voltage over temperature
10
30
mV
ΔV REF
----------------ΔV Z
Ratio of the change in
reference voltage to the
change in cathode voltage
-1.85
-2.7
mV/V VZ from VREF to 10V
IZ=10mA (Fig.2)
-1.0
-2.0
mv/V VZ from 10V to 20V
IZ=10mA (Fig.2)
IREF
Reference input current
0.12
1.0
mA
R1=10k, R2=O/C,
lL=10mA (Fig.2)
DIREF
Deviation of reference input
current over temperature
0.04
0.2
mA
R1=10k, R2=O/C,
IL=10mA Tamb=full range
(Fig.2)
IZmin
Minimum cathode current for
regulation
35
50
mA
VZ=VREF (Fig.1)
IZoff
Off-state current
0.1
mA
VZ=20V, VREF=0V(Fig.3)
RZ
Dynamic output impedance
0.75
V
VZ=VREF (Fig.1), f=0Hz,
IC=1mA to 100mA
IL=10mA, VZ=VREF
Tamb=full range (Fig1)
Deviation of reference input voltage, VDEV, 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, VREF is defined as:
V DEV x 1000000
ppm
V REF ⎛ ----------- ⎞ = -------------------------------------⎝ °C ⎠
V REF ( T1 – T2 )
Vmax
The dynamic output impedance, RZ, is defined as:
RZ
ΔV
= --------ZΔ IZ
Vmin
Vdev = Vmax - Vmin
When the device is programmed with two externalresistors, R1 and R2,
(fig 2) , the dynamic outputimpedance of the overall circuit, R’, is
defined as:
R′
T1
Temperature
T2
= R Z ( 1 + R1
------- )
R2
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ZHT431
Typical Characteristics
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ZHT431
Typical Characteristics
Open Loop Voltage Gain (dB)
60
VZ
IZ
230
40
15k
9µF
+
20
8k25
-
0
100
1k
10k
100k
1M
IZ = 10mA, TA = 25°C
Frequency (Hz)
Gain v Frequency
Test Circuit for Open Loop Voltage Gain
220
Input Monitor
3.0
VZ
Voltage Swing (V)
Repetitive pulse
2.0
Single pulse
VZ
1.0
Pulse
Generator
0
5.0
INPUT
0
0
0.2
0.4
0.6
0.8
1.0
Time (µs)
TA = 25°C
Test Circuit for Pulse Response
Pulse Response
100
Input
Cathode Current (mA)
50
80
150
VZ
IZ
STABLE
STABLE
10k
60
40
20
0
10p
100p
1000p
0.01µ
0.1µ
1µ
Load Capacitance (F)
Stability Boundary Conditions
Vref < VZ < 20, IZ = 10mA, TA = 25°C
Test Circuit for Stability Boundary Conditions
4-31
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ZHT431
DC Test Circuits
IL
VZ
Input
IZ
IL
IZ
Iref
R1
Iref
Vref
R2
Vref
Fig 1 - Test circuit for VZ = Vref
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VZ
Input
Fig 2 - Test circuit for VZ > Vref
6
Input
IZOFF
Fig 3 - Test circuit for for Of
state current†
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ZHT431
Application Circuits
V+Vout
V+Vout
R1
R1
Vref
Vref
R2
R2
Vout=
1+
R1
Vref
Vout=
R2
1+
R1
Vref
R2
Shunt regulator
Higher current shunt regulator
V+
ZSR***
+
Vout
Out
In
30⍀
Common
R1
0.01µF
Vref
R1
R2
Vref
Vout
R2
Vout MIN = Vref + Vreg
Vout=
1+
R1
Vref
R2
Vout=
1+
R1
Series regulator
V+
V+
R1B
R1A
Output
Input
Vref
R2
Output control of a
three terminal fixed regulator
V on
2V
Vref
Output
Vref
V off = V+
V TH = 2.5V
R2A
R2B
Low limit =
Single supply comparator
with temperature
compensated threshold
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1+
High limit = 1 +
R1B
Vref
R2B
R1A
Vref
R2A
Over voltage / under voltage
protection circuit
7
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ZHT431
Package Outline - TO92
DIM
Millimeters
Inches
Min.
Max.
Min.
Max.
A
4.32
4.95
0.170
0.195
b
0.36
0.51
0.014
0.020
E
3.30
3.94
0.130
0.155
e
2.41
2.67
0.095
0.105
e1
1.14
1.40
0.045
0.055
L
12.70
15.49
0.500
0.610
R
2.16
2.41
0.085
0.095
S1
1.14
1.52
0.045
0.060
W
0.41
0.56
0.016
0.022
D
4.45
4.95
0.175
0.195
*°
4°
6°
4°
6°
Note: Controlling dimensions are in millimeters. Approximate dimensions are provided in inches
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ZHT431
Package outline - SOT23
E
e
e1
b
3 leads
L1
D
E1
A
A1
Dim.
L
c
Millimeters
Inches
Dim.
Millimeters
Min.
Max.
Inches
Min.
Max.
Min.
Max.
A
-
1.12
-
0.044
e1
A1
0.01
0.10
0.0004
0.004
E
2.10
2.64
0.083
0.104
b
0.30
0.50
0.012
0.020
E1
1.20
1.40
0.047
0.055
c
0.085
0.20
0.003
0.008
L
0.25
0.60
0.0098
0.0236
D
2.80
3.04
0.110
0.120
L1
0.45
0.62
0.018
0.024
e
0.95
NOM
0.037
NOM
-
-
-
-
-
1.90 NOM
Min.
Max.
0.075 NOM
Note: Controlling dimensions are in millimeters. Approximate dimensions are provided in inches
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ZHT431
Package outline - SOT223
Dim.
Millimeters
Inches
Dim.
Millimeters
Inches
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
A
-
1.80
-
0.071
D
6.30
6.70
0.248
0.264
A1
0.02
0.10
0.0008
0.004
e
2.30 BSC
0.0905 BSC
A2
1.55
1.65
0.0610
0.0649
e1
4.60 BSC
0.181 BSC
b
0.66
0.84
0.026
0.033
E
6.70
7.30
0.264
0.287
b2
2.90
3.10
0.114
0.122
E1
3.30
3.70
0.130
0.146
C
0.23
0.33
0.009
0.013
L
0.90
-
0.355
-
Note: Controlling dimensions are in millimeters. Approximate dimensions are provided in inches
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ZHT431
IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTIC ULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
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without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume
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Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and
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indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.
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noted herein may also be covered by one or more United States, international or foreign trademarks.
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Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B.
A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
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