ZR431
ADJUSTABLE PRECISION ZENER SHUNT REGULATOR
Description
The ZR431 is a three terminal adjustable shunt regulator
offering excellent temperature stability and output current
handling capability up to 100mA. The output voltage may be
set to any chosen voltage between 2.5 and 20 volts by
selection of two external divider resistors.
Pin Assignments
(Top View)
V
REF
3
1 GND
V
Z
2
SOT23
(Top View)
V
Z
1
GND 2
V
REF
3
SOT223
Pin 4 floating or
connected to pin 2
4 GND
ADVANCE INFORMATION
The devices can be used as a replacement for zener diodes
in many applications requiring an improvement in zener
performance.
Features
•
•
•
•
•
•
•
•
•
Surface mount SOT223 and SOT23 packages
2%, 1 % and 0.5% tolerance
Max. temperature coefficient 55 ppm/°C
Temperature compensated for operation
over the full temperature range
Programmable output voltage
50μA to 100mA current sink capability
Low output noise
All package options available in “Green” Molding
Compound (No Br, Sb) and Lead Free Finish/ RoHS
Compliant (Note 1)
1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html.
Applications
•
•
•
•
•
Shunt regulator
Series regulator
Voltage monitor
Over voltage/ under voltage protection
Switch mode power supplies
Notes:
Typical Application Circuit
V
Z
V
REF
+
GND
ZR431
Document number: DS33255 Rev. 6 - 2
1 of 9
www.diodes.com
October 2011
© Diodes Incorporated
ZR431
ADJUSTABLE PRECISION ZENER SHUNT REGULATOR
Absolute Maximum Ratings
(Note 2)
Symbol
V
Z
I
Z
T
A
Cathode Voltage
Cathode Current
Operating Temperature
Storage Temperature
Power Dissipation (Notes 3, 4)
SOT23
SOT223
Parameter
Rating
20
150
-40 to +85
-55 to +125
330
2
Unit
V
mA
°
°
C
C
ADVANCE INFORMATION
T
ST
P
D
Notes:
mW
W
2. Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may
reduce device reliability. Unless otherwise stated voltages specified are relative to the ANODE pin.
3. T
J
, max =150°C.
4. Ratings apply to ambient temperature at 25°C.
Recommended Operating Conditions
(T
A
= 25°C)
Symbol
V
Z
I
Z
Cathode Voltage
Cathode Current
Parameter
Min
V
REF
0.05
Max
20
100
Unit
V
mA
Electrical Characteristics
(T
A
= 25°C unless otherwise specified)
Symbol
V
REF
Parameter
Reference voltage (Note 5)
2%
1%
0.5%
Test Conditions
I
L
= 10mA (Fig 1), V
Z
= V
REF
Min
2.45
2.475
2.487
Typ.
2.50
2.50
2.50
8.0
-1.85
-1.0
0.12
0.04
35
Max
2.55
2.525
2.513
17
-2.7
mV/V
-2.0
1.0
0.2
50
0.1
0.75
μA
μA
µA
μA
Ω
Unit
V
V
DEV
Deviation of reference input voltage I
L
= 10mA, V
Z
= V
REF
over temperature
T
A
= Full range (Fig 1)
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
0.5% and 1% SOT23 only
mV
V
Z
from V
REF
to 10V
I
Z
= 10mA (fig 2)
V
Z
from 10V to 20V
I
Z
= 10mA (Fig 2)
R1 = 10k, R2 = O/C, I
L
= 10mA (Fig 2)
R1 = 10k, R2 = O/C, I
L
= 10mA
T
A
= Full range (Fig 2)
V
Z
= V
REF
(Fig 1)
V
Z
= 20V, V
REF
= 0V (Fig 3)
V
Z
= V
REF
(Fig 1), f = 0Hz
ΔV
REF
ΔV
Z
I
REF
ΔI
REF
I
Z(MIN)
I
Z(OFF)
R
Z
Note 5:
For definitions of reference voltage temperature coefficient and dynamic output impedance see NOTES following DC TEST CIRCUITS
ZR431
Document number: DS33255 Rev. 6 - 2
2 of 9
www.diodes.com
October 2011
© Diodes Incorporated
ZR431
ADJUSTABLE PRECISION ZENER SHUNT REGULATOR
DC Test Circuits
I
L
Input
V
Z
Input
I
L
V
Z
Input
V
Z
I
ZOFF
ADVANCE INFORMATION
I
Z
I
REF
R1
I
Z
I
REF
V
REF
R2
V
REF
Fig. 1 Test Circuit for V
Z
= V
REF
Fig. 2 Test Circuit for V
Z
> V
REF
Fig.3 Test Circuit for Off State Current
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
MAX
V
ref
(ppm /
o
C)
=
V
dev
×
1000000
V
ref
(T1
−
T2)
The dynamic output impedance, RZ is defined as:
V
MIN
V
DEV
= V
MAX
- V
MIN
R
z
=
Δ
V
z
Δ
I
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
+
R1
)
R2
T1
Temperature
T2
ZR431
Document number: DS33255 Rev. 6 - 2
3 of 9
www.diodes.com
October 2011
© Diodes Incorporated
ZR431
ADJUSTABLE PRECISION ZENER SHUNT REGULATOR
Typical Characteristics
160
140
140
130
CHANGE in REFERENCE OUTPUT
VOLTAGE (mV)
V
REF
= V
Z
I
Z
= 10mA
0
I
Z
= 10mA
REFERENCE CURRENT (nA)
-5
ADVANCE INFORMATION
-10
-15
120
110
-20
100
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
Reference Current vs. Temperature
-25
5
10
15
CATHODE VOLTAGE (V)
Change in V
REF
vs. Cathode Voltage
20
38
MINIMUM CATHODE CURRENT (µA)
V
REF
= V
Z
100
36
34
32
30
28
26
24
-40
DYNAMIC IMPEDANCE (
Ω
)
10
1.0
-20
0
20
40
60
80
TEMPERATURE (°C)
Cathode Current vs. Temperature
0.1
100
10k
100k
FREQUENCY (Hz)
Dynamic Impedance vs. Frequency
1k
1M
2.506
2.504
REFERENCE VOLTAGE (V)
2.502
2.500
2.498
2.496
2.494
2.492
2.490
-40
20
40
0
60
80
TEMPERATURE (°C)
Reference Voltage vs. Temperature
-20
I
Z
= 10mA
2.0
POWER DISSIPATION (W)
SOT223
1.0
SOT23
0
25
50
75 85
AMBIENT TEMPERATURE (
°
C)
Power Dissipation Derating
100
ZR431
Document number: DS33255 Rev. 6 - 2
4 of 9
www.diodes.com
October 2011
© Diodes Incorporated
ZR431
ADJUSTABLE PRECISION ZENER SHUNT REGULATOR
Typical Characteristics
(cont.)
60
V
Z
OPEN LOOP VOLTAGE GAIN (dB)
I
Z
40
9µF
15k
230
ADVANCE INFORMATION
+
20
8k25
-
0
100
1k
10k
100k
FREQUENCY (Hz)
Gain vs. Frequency
1M
I
Z
= 10mA, T
A
= 25°C
Test Circuit for Open Loop Voltage Gain
Input Monitor
220
V
Z
3.0
Repetitive Pulse
VOLTAGE SWING (V)
2.0
Single Pulse
V
Z
1.0
Pulse
Generator
50
0
5.0
INPUT
0
T
A
= 25°C
0
0.2
0.4
0.6
TIME (µs)
Pulse Response
0.8
1.0
Test Circuit for Pulse Response
Input
150
V
Z
100
CATHODE CURRENT (mA)
80
STABLE
STABLE
I
Z
10k
60
40
20
0
10p
100p
1000p 0.01µ
0.1µ
LOAD CAPACITANCE (F)
Stability Boundary Conditions
1µ
V
REF
< V
Z
< 20, I
Z
= 10mA, T
A
= 25°C
Test Circuit for Stability Boundary Conditions
ZR431
Document number: DS33255 Rev. 6 - 2
5 of 9
www.diodes.com
October 2011
© Diodes Incorporated
