Not Recommended for New Design
Please Use ZR431
ADJUSTABLE PRECISION
ZENER SHUNT REGULATOR
ZH431
Issue 2 - February 1998
DEVICE DESCRIPTION
FEATURES
The ZH431 is a three terminal adjustable
s hu n t r e g u l a t or o f f e r i n g e xc el l e nt
temperature stability and output current
handling capability up to 30mA. The output
voltage may be set to any chosen voltage
between 2.5 and 36 volts by selection of two
external divider resistors.
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•
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•
•
The devices can be used as a replacement
for zener diodes in many applications
r e qu i r i n g a n i mpr o ve me nt i n z e ner
performance.They are also ideal for use in
the feedback circuits of off line SMPUs as
well as many general purpose regulator and
reference applications where initial accuracy
and low temperature coefficient are key
requirements.
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•
•
Surface mount SO8, SOT223,SOT23
and SOT89 packages
TO92 package
2% and 1% tolerance
Maximum temperature coefficient 55
ppm/°C
Temperature compensated for
operation over the full temperature
range
Programmable output voltage
50µA to 30mA current sink capability
Low output noise
APPLICATIONS
•
•
•
•
•
Note:
ZH431 is not recommended for new designs.
Refer to ZR431
Shunt regulator
Series regulator
Voltage monitor
Over voltage/ under voltage protection
Switch mode power supplies
SCHEMATIC DIAGRAM
VZ
V ref
Gnd
4-15
Not Recommended for New Design
Please Use ZR431
ZH431
ABSOLUTE MAXIMUM RATING
Cathode Voltage (VZ)
40V
Cathode Current
50mA
Operating Temperature
-40 to 85°C
Storage Temperature
-55 to 125°C
Recommended Operating Conditions
Min Max
Cathode Voltage
Vref 36V
Cathode Current
50µA 30mA
Power Dissipation (Tamb=25°C, Tjmax=150°C)
SOT23
330mW
TO92
780mW
SOT223
2W
SO8
780mW
SOT89
1.5W
ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise
stated):Tamb=25°C
VALUE
SYMBOL
PARAMETER
MIN
Reference Voltage
2% Vref
1%
TYP MAX UNITS CONDITIONS
2.45 2.50 2.55 V
2.475 2.50 2.525
IL=10mA (Fig1), VZ=Vref
Deviation of Reference
Input Voltage over
Temperature
Vdev
8.0
17
mV
IL=10mA, VZ=Vref
Ta=full range (Fig1)
Ratio of the change in
Reference Voltage to the
Change in Cathode
Voltage
∆Vref
∆VZ
-0.7
-2.7
mV/V
VZ from Vref to 10V
IZ=10mA (Fig2)
-0.6
-2.0
mV/V
VZ from 10V to 36V
IZ=10mA (Fig2)
Reference Input Current
Iref
0.15 1.0
µA
R1=10k, R2=O/C, lL=10mA (Fig2)
Deviation of Reference
Input Current over
Temperature
∆Iref
0.06 0.2
µA
R1=10k, R2=O/C, IL=10mA
Ta=full range (Fig2)
Minimum Cathode
Current for Regulation
IZmin
21
50
µA
VZ=Vref (Fig1)
0.75
Ω
VZ=Vref (Fig1), f=0Hz
Dynamic Output Impedance RZ
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:
Vdev x 1000000
Vref (T1−T2)
The dynamic output impedance, Rz, is defined as:
∆VZ
RZ =
∆IZ
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:
R1
R’=Rz (1+ )
R2
Vref (ppm ⁄ °C)=
Vmax
Vmin
Vdev = Vmax - Vmin
T1
Temperature
T2
4-16
Not Recommended for New Design
Please Use ZR431
ZH431
TYPICAL CHARACTERISTICS
200
Change in Reference Voltage (mV)
5
Reference Current (nA)
Vref= Vz
Iz= 10mA
180
160
140
120
100
-40
-20
0
20
40
80
60
Temperature (°C)
26
Vref= Vz
24
22
20
18
16
14
12
-40
-20
0
20
40
80
60
-5
-10
-15
-20
-25
0
5
10
15
20
25
30
40
35
Cathode Voltage (V)
Change in Vref v Cathode Voltage
Dynamic Impedance (Ohms)
Minimum Cathode Current (uA)
Reference Current v Temperature
0
100
1mA
10
Vref=Vz
10mA
1
0.1
0.01
100
Temperature (°C)
10k
1k
100k
1M
Frequency (Hz)
Dynamic Impedance v Frequency
Cathode Current v Temperature
2.52
2.0
Power Dissipation (W)
Iz= 10mA
Reference Voltage (V)
2.51
2.50
2.49
2.48
2.47
-40
-20
0
20
40
60
SOT223
1.0
SOT89
S08/T092
SOT23
0
25
80
50
75
Ambient Temperature (°C)
Temperature (°C)
Power Dissipation Derating
Reference Voltage v Temperature
4-17
100
Not Recommended for New Design
Please Use ZR431
ZH431
TYPICAL CHARACTERISTICS
VZ
70
50
Open Loop Gain (dB)
IZ
15k
60
230Ω
9µF
40
+
30
8k25
20
-
10
0
100
10k
1k
100k
1M
IZ = 10mA, TA = 25°C
Frequency (Hz)
Gain v Frequency
Test Circuit for Open Loop Voltage Gain
220Ω
Input Monitor
3.0
VZ
REPETITIVE
PULSE
Voltage Swing (V)
2.0
SINGLE
PULSE
Pulse
Generator
1.0
50Ω
0
5
INPUT
0
TA = 25°C
0
0.05
0.1
0.15
0.2
0.25
Time (µs)
Pulse Response
Test Circuit for Pulse Response
Input
30
Cathode Current (mA)
25
VZ
IZ
20
Unstable
15
150
10k
Stable
Stable
10
5
0
10p
100p
1000p
0.01µ
0.1µ
1µ
Load Capacitance (F)
Stability Boundary Conditions
Vref < VZ < 40, IZ = 10mA, TA = 25°C
Test Circuit for Stability Boundary Conditions
4-18
Not Recommended for New Design
Please Use ZR431
ZH431
DC TEST CIRCUITS
IL
Input
Fig 1 – Test Circuit for Vz=Vref
Fig 2 – Test Circuit for Vz>Vref
4-19
Not Recommended for New Design
Please Use ZR431
ZH431
APPLICATION CIRCUITS
V+
Vout
V+
Vout
R1
R1
Vref
Vref
R2
Vout =
R2
R1
1+
Vref
Vout =
R2
1+
R1
Vref
R2
SHUNT REGULATOR
HIGHER CURRENT SHUNT REGULATOR
V+
ZSR***
V+
Vout
Out
In
Common
30
R1
0.01µF
Vref
R1
R2
Vout
Vref
R2
Vout MIN = Vref + Vreg
Vout =
1+
R1
Vref
R2
Vout =
1+
R1
Vref
R2
OUTPUT CONTROL OF A
THREE TERMINAL FIXED REGULATOR
SERIES REGULATOR
V+
V+
R1A
OUTPUT
R1B
Vref
INPUT
V on
2V
Vref
V off = V+
R2A
V TH = 2.5V
R2B
Low limit =
High limit =
SINGLE SUPPLY COMPARATOR
WITH TEMPERATURE
COMPENSATED THRESHOLD
1+
R1B
Vref
R2B
1+
R1A
Vref
R2A
OVER VOLTAGE / UNDER VOLTAGE
PROTECTION CIRCUIT
4-20
OUTPUT
Not Recommended for New Design
Please Use ZR431
ZH431
CONNECTION DIAGRAMS
SO8 Package Suffix – N8
SOT223 Package Suffix – G
Top View
Top View –
Pin 4 floating or connected to pin 2
SOT23 Package Suffix – F
TO92 Package Suffix – C
Top View
Bottom View
SOT89
ORDERING INFORMATION
Part Number
Package
Tol.
%
Part Mark
ZH431C01
TO92
1.0
ZH43101
ZH431C02
TO92
2.0
ZH43102
ZH431G01
SOT223
1.0
ZH43101
ZH431G02
SOT223
2.0
ZH43102
ZH431F01
SOT23
1.0
43H
ZH431F02
SOT23
2.0
43G
ZH431Z01
SOT89
1.0
43H
ZH431Z02
SOT89
2.0
43G
ZH431N801
SO8
1.0
ZH43101
ZH431N802
SO8
2.0
ZH43102
Package Suffix – Z
Top View –
Pin 4 floating or connected to pin 2
4-21