ETC CYT431

Adjustable Precision
Shunt Regulator
Description
CYT431
Features
The CYT431 is a low voltage three terminal ¾
Low voltage operation (2.5V)
adjustable shunt regulator with a guaranteed thermal
¾
Adjustable output voltage V0 = VREF to 18V
stability over applicable temperature ranges. The output
¾
Wide operating current range 120µA to 100mA
voltage can be set to any value between VREF
¾
Low dynamic output impedance 0.2Ω (Typ.).
(approximately 2.5 V) to 18V with two external resistors.
¾
Trimmed bandgap design up to + 0.5%.
This device has a typical output impedance of 0.2Ω.
¾
ESD rating is 5.5KV(Per MIL-STD-883D).
Active output circuitry provides a very sharp turn on
¾
Available in Lead Free Packages.
characteristic, making this device excellent replacement
for Zener diodes in many applications.
The CYT431 is characterized for operation from 0oC
to 105oC, and five package options (SOT-23-3, SOT-23-5,
SOP-8, TO-92 and SOT-89) allow the designer the
opportunity to select the proper package for their
applications.
Application
¾
Linear Regulators
¾
Adjustable Supplies
¾
Switching Power Supplies
¾
Battery Operated Computers
¾
Instrumentation
¾
Computer Disk Drives
Block Diagram
Symbol Diagram
Cathode
Ref
Cathode
+
Ref
Vref
Anode
Anode
All contents are subject to change without prior notice.
1
Adjustable Precision
Shunt Regulator
CYT431
Marking Information
Package
SOT-23-3
SC59-3L
SOT-23-3
SOT-23-5L
SOP-8
SOT-89
TO-92
Marking
Production Year Code
Production Week Code
Lead-Free Package
Starting with S, a bar on top of S is for production
431
year 2001, and underlined S is for year 2002.
431
The next character is marked on top for 2003, and
(431S)
underlined for 2004. The naming pattern continues
431W
with consecutive characters for later years.
Lead-free package is
A-Z: 1-26
indicated by a dot on
a-z: 27-52
top of the week code.
CYT431
WW
YYWW
is
the
week
of
CYT431
YY is the year of production. 04 means the
production.
YYWW
product is manufactured in year of 2004.
product is manufactured in
26 means the
the 26th week.
CYT431
Lead-free
package
indicated by LF after
YYWW.
YYWW
Pin Configuration
SOT-23-3
SOT-23-3
SOT-23-3L (SC59-3L)
(Order as CYT431S)
SOT-23-5L
TO-92
SOP-8
(Top View)
is
SOT-89
All contents are subject to change without prior notice.
2
Adjustable Precision
Shunt Regulator
CYT431
Absolute Maximum Ratings
Parameter
Symbol
Maximum
Units
Cathode Voltage
VKA
18
V
Continuous Cathode Current
I KA
150
mA
Reference Current
I REF
10
mA
TJ
150
°C
TSTG
-65 to 150
°C
Operating Junction Temperature Range
Storage Temperature Range
120 (SOT-89)
230 (SOT-23-3)
θ JA
Thermal Resistance
°C/W
230 (SOT-23-5L)
150 (SOP-8)
220 (TO-92)
Lead Temperature (Soldering) 10 seconds
TLEAD
260
°C
Electrical Characteristics
TEST
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
2483
2495
2507
2470
2495
2520
2445
2495
2545
--
4
25
mV
--
-1.4
-2.7
mV/V
--
2
4
µA
--
0.4
1.2
µA
CIRCUIT
0.5%
Reference Voltage
VREF
1%
1
VKA = VREF, IKA = 10mA
2%
Deviation of reference voltage over
VI(dev)
full temperature range
1
VKA = VREF, IKA = 10mA
mV
TA = 0°C to 105°C
Ratio of change in reference
∆ VREF
voltage to the change in cathode
________
voltage
∆ VKA
Reference current
IREF
2
II(dev)
2
IMIN
1
VKA = VREF
--
0.2
1
mA
Off-state cathode current
IOFF
3
VKA = 18V, VREF = 0
--
0.1
1
µA
Dynamic impedance
ZKA
1
--
0.2
0.7
Ω
2
Deviation of Reference current
over full temperature range
Minimum cathode current
regulation
IKA = 10mA,
∆VKA = 10 V - VREF
IKA = 10mA,
R1=10kΩ, R2 = ∞
IKA = 10mA, R1=10kΩ,
R2 = ∞, TA = 0°C to 105°C
for
IKA = 1mA to 100mA, VKA =
VREF, f ≤ 1kHZ
All contents are subject to change without prior notice.
3
Adjustable Precision
Shunt Regulator
CYT431
Typical Performance Characteristics
CATHODE CURRENT
CATHODE CURRENT
Vs.
Vs.
CATHODE VOLTAGE
CATHODE VOLTAGE
800
125
VKA = Vref
100
TA = 25 oC
V K A = V ref
TA = 25 o C
600
Cathode Current (µA)
Cathode Current (mA)
150
75
50
25
0
-25
400
200
-50
0
-75
-100
-2
-1
0
1
2
- 200
3
-1
0
Cathode Voltage (V)
3
REFERENCE VOLTAGE
REFERENCE INPUT CURRENT
Vs.
Vs.
JUNCTION TEMPERATURE
JUNCTION TEMPERATURE
3
VKA =Vref
Reference Current (µA)
Reference Voltage (mV)
2
Cathode Voltage (V)
2520
2515
1
IKA =10mA
2510
2505
2500
2495
2490
2485
2480
- 60 - 40 - 20
0
20 40
60
80 100 120
Junction Temperature ( oC)
2. 5
R1 = 10k Ω
R2 = ∞
I KA =10mA
2
1. 5
1
0. 5
0
- 20
0
20
40
60
80
100
120
o
Junction Temperature ( C)
All contents are subject to change without prior notice.
4
Adjustable Precision
Shunt Regulator
CYT431
Test Circuits
Input
Input
V KA
Input
VKA
VKA
I off
I KA
I KA
R1
Iref
R2
Vref
Vref
R1
VKA = Vref (1+ ) + Iref x R1
R2
Test Circuit 1:
Test Circuit 2:
Test Circuit 3:
VKA = VREF
VKA > VREF
Off State Current
Application Diagram
VIN
R
VOUT
R1
CYT431
Vref
R1
)
R2
VOUT = Vref (1+
R2
GND
Thermal Consideration
Package
Power Rating
Power Rating
Power Rating
(TA=25°C)
(TA=50°C)
(TA=70°C)
SOT-23-3 (θJA=230°C/W)
435mW
326mW
239mW
SOT-23-5L (θJA=230°C/W)
435mW
326mW
239mW
TO-92 (θJA=220°C/W)
455mW
341mW
250mW
1. Maximum junction temperature is 125°C
2. θJA is measured with packages mounted onboard under still-air condition with 1W power applied.
3. Power rating is calculated using PD = (TJ – TA) /θJA, where TJ denotes junction temperature and TA denotes ambient temperature.
All contents are subject to change without prior notice.
5
Adjustable Precision
Shunt Regulator
CYT431
OUTLINE DRAWING SOT-23-3
C
DIMENSIONS
INCHES
MM
MIN
MAX
MIN
MAX
J
H
B
N
DIM
A
B
C
D
E
F
G
H
J
K
L
D
A
E
G
F
K
L
0.110
0.047
0.083
0.035
0.070
0.018
0.015
0.0005
0.034
0.003
-
0.120
0.055
0.104
0.040
0.080
0.024
0.020
0.004
0.040
0.007
0.027
2.80
1.20
2.10
0.89
1.78
0.45
0.37
0.013
0.887
0.085
-
3.04
1.40
2.64
1.03
2.05
0.60
0.51
0.10
1.02
0.18
0.69
OUTLINE DRAWING SC59-3L (SOT-23-3L)
H
DIM
A
A
A1
B
C
D
H
E
e
e1
L1
L
Q
E
A1
B
e1
D
L
SC 59-3L
Q
L1
C
N
DIMENSIONS
INCHE
MM
MIN
MAX
MIN
MAX
0.035 0.043 0.90
1.10
0.0004 0.005
0.01
0.13
0.012 0.020 0.30
0.50
0.004 0.008 0.09
0.20
0.110 0.122 2.80
3.10
0.098 0.122 2.50
3.10
0.059 0.067 1.50
1.70
0.037REF
0.075REF
0.008
0.014
0℃
0.022
0.031
10℃
0.95REF
1.90REF
0.20
0.35
0℃
0.55
0.80
10℃
OUTLINE DRAWING SOT-23-5L
K
B
H
D
A
F
E
C
J
DIMN
A
B
C
D
E
F
H
J
K
DIMENSIONS
INCHES
MM
MIN MAX MIN MAX
0.110
0.059
0.036
0.014
0.0035
0.102
0.120
0.070
0.051
0.020
0.037
0.075
0.006
0.008
0.118
2.80
1.50
0.90
0.35
0.090
2.60
3.05
1.75
1.30
0.50
0.95
1.90
0.15
0.20
3.00
All contents are subject to change without prior notice.
6
Adjustable Precision
Shunt Regulator
CYT431
OUTLINE DRAWING TO-92
DIMENSIONS
INCHES
MM
MIN MAX MIN MAX
A
DIMN
B
D
A
B
E
F
G
H
J
K
E
G
F
H
K
J
0.175
0.170
0.500
0.016
0.045
0.095
0.080
0.125
0.205
0.210
0.610
0.021
0.055
0.105
0.105
0.165
4.445
4.318
12.70
0.407
1.143
2.413
2.032
3.175
5.207
5.334
15.50
0.533
1.397
2.667
2.667
4.191
OUTLINE DRAWING SOP-8
1
8
2
7
3
6
4
5
D
B
N
DIM
B1
A1
A
E
H
C
A
A1
B
B1
C
D
H
E
DIMENSIONS
INCHES
MM
MIN MAX MIN MAX
0.0532 0.0688
0.0040 0.0098
0.0130 0.0200
0.050 BSC
0.0075 0.0098
0.1890 0.1968
0.2284 0.2440
0.1497 0.1574
1.35
1.75
0.10
0.25
0.33
0.51
1.27 BSC
0.19
0.25
4.80
5.00
5.80
6.20
3.80
4.00
OUTLINE DRAWING SOT-89
N
DIM
SOT-89
A
C
D
J
M
K
E
F
B
L
H
G
I
A
B
C
D
E
F
G
H
I
J
K
L
M
DIMENSIONS
INCHES
MM
MIN
MAX
MIN
MAX
0.173 0.181
0.159 0.167
0.067 0.075
0.051 0.059
0.094 0.102
0.035 0.047
0.118REF
0.059REF
4.400 4.600
4.050 4.250
1.700 1.900
1.300 1.500
2.400 2.600
0.890 1.200
3.00REF
1.50REF
0.016 0.020
0.055 0.063
0.014 0.016
10°TYP
0.028REF
0.400 0.520
1.400 1.600
0.350 0.410
10°TYP
0.70REF
All contents are subject to change without prior notice.
7