CM431A
L
OW
V
OLTAGE
A
DJUSTABLE
S
HUNT
R
EGULATOR
GENERAL DESCRIPTION
The CM431A is a three-terminal adjustable shunt voltage
regulator with specified thermal stability and pin-to-pin compatible
with the earlier 431 series. The output voltage can be adjusted to
any value between V
REF
and 18V by using two external resistors.
The CM431A offers low output impedance for improved load
regulation with a typical output impedance of 200mΩ. Because
of the active output circuitry, the CM431A can replace the zener
diodes in applications such as switching power supplies, OVP
crowbar circuits, references for A/D, D/A converters with
improved turn-on characteristics.
Voltage Reference
Precision shunt regulator
High current shunt regulator
PWM down converter with reference
Voltage monitor
FEATURES
Initial voltage reference accuracy of 1.0%.
Sink current capability from 1mA to 100mA
Typical output dynamic impedance less than 200mΩ;
Adjustable output voltage from V
REF
to 18V
Available in SOT-23, SOT-89, TO-92, & SOP-8
Low output noise
Typical equivalent full range temperature coefficient of
30ppm/
O
C
APPLICATIONS
PIN CONFIGURATION
TO-92
Front View
SOT-23-3
Top View
3
CATHODE
REF
ANODE
CM431AXCM233 CM431AXCM2R3
Pin 1
Pin 2
Pin 3
1
2
REF
CATHODE
ANODE
CATHODE
REF
ANODE
Suffix “X”: Grade “A”, “B”, “C”, or “D”
1
2
3
SOT-23-5
Top View
5
4
SOT-89
Top View
1
SOP-8
Top View
C OE
ATH D
N
C
N
C
N
C
R
EF
N
C
AN D
OE
N
C
8
7
6
5
CATHODE REF
CATHODE
ANODE
REF
ANODE
2
3
4
NC
NC
1
2
3
1
2
3
2004/08/05
Preliminary
Champion Microelectronic Corporation
Page 1
CM431A
L
OW
V
OLTAGE
A
DJUSTABLE
S
HUNT
R
EGULATOR
TYPICAL APPLICATION
V+
R
b
R1
27.5K
0.1%
R2
27.5K
0.1%
V
REF
ANODE
5V Precision Regulator
V
O
= 5V
CATHODE
BLOCK DIAGRAM
REF
Note: R
b
should
provide cathode
current
≥
1mA
+
-
2004/08/05
Preliminary
Champion Microelectronic Corporation
Page 2
CM431A
L
OW
V
OLTAGE
A
DJUSTABLE
S
HUNT
R
EGULATOR
ORDERING INFORMATION
PACKAGE
0.5%
SOT-23-3
（
1
）
SOT-23-3
（
1
）
SOT-23-5
（
1
）
SOT-89
（
1
）
TO-92
（
2
）
SOP-8
SOT-23-3
（
1
）
SOT-23-3
（
1
）
SOT-23-5
（
1
）
SOT-89
（
1
）
TO-92
（
2
）
SOP-8
Notes：
（1）
Add suffix
″TR″for
Tape & Reel.
（2）
Add suffix
″TA″for
Tape Ammo.
（3）
CM431AACM233
CM431AACM2R3
CM431AACM235
CM431AACM89
CM431AACN
CM431AACS
CM431AGACM233*
CM431AGACM2R3*
CM431AGACM235*
CM431AGACM89*
CM431AGACN*
CM431AGACS*
1.0%
CM431ABCM233
CM431ABCM2R3
CM431ABCM235
CM431ABCM89
CM431ABCN
CM431ABCS
CM431AGBCM233*
CM431AGBCM2R3*
CM431AGBCM235*
CM431AGBCM89*
CM431AGBCN*
CM431AGBCS*
TOLERANCE
1.5%
CM431ACCM233
CM431ACCM2R3
CM431ACCM235
CM431ACCM89
CM431ACCN
CM431ACCS
CM431AGCCM233*
CM431AGCCM2R3*
CM431AGCCM235*
CM431AGCCM89*
CM431AGCCN*
CM431AGCCS*
TR=3K
TR=3K
TR=3K
TR=1K
TA=2K
T/R Quantity
TR=3K
TR=3K
TR=3K
TR=1K
TA=2K
*Note:
Add
suffix “G” for Pb Free Product
2004/08/05
Preliminary
Champion Microelectronic Corporation
Page 3
CM431A
L
OW
V
OLTAGE
A
DJUSTABLE
S
HUNT
R
EGULATOR
ABSOLUTE MAXIMUM RATINGS
Cathode to Anode Voltage (V
KA
) (Note 2)
Continuous Cathode Current (I
K
)
Reference Input Current (I
REF
)
Maximum junction temperature range, T
J
Storage temperature range
Lead temperature (soldiering, 10 seconds)
Note 1:
Note 2:
Currents are positive into, negative out of the specified terminal.
Voltage values are with respect to the anode terminal unless otherwise noted.
-0.3V to 18V
-100mA to 150mA
-50uA to 10mA
150
O
C
-65
O
C to 150
O
C
260
O
C
Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground.
POWER DISSIPATION TABLE
Package
SOP-8
TO-92
SOT-89
θ
JA
O
( C/W )
165
156
71(note)
Derating factor ( mW/
O
C )
T
A
≧25
O
C
6.06
6.41
14.1
T
A
≦25
O
C
Power rating(mW)
757
801
1763
T
A
=70
O
C
Power rating(mW)
485
513
1128
T
A
= 85
O
C
Power rating (mW)
394
417
916
228
SOT-23
285
3.5
438
280
Note :
1. For SOT-89 package, Thermal Resistance-Junction to Tab (
θ
JT
) = 35
O
C/W. T
J
= T
TAB
+ (P
D
x
θ
JT
)
2.
θ
JA
:
Thermal Resistance-Junction to Ambient
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
The
θ
JA
numbers are guidelines for the thermal performance of the device/PC-board system.
All of the above assume no ambient airflow.
RECOMMENDED OPERATING CONDITIONS
Min
Operating free air temperature range, T
A
Cathode current, I
K
Cathode voltage, V
KA
0
1
0
Max
105
100
16
Units
O
C
mA
V
2004/08/05
Preliminary
Champion Microelectronic Corporation
Page 4
CM431A
L
OW
V
OLTAGE
A
DJUSTABLE
S
HUNT
R
EGULATOR
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, these specifications apply over the operating ambient temperatures with T
A
= 25°C.
Parameter
Symbol
Test Conditions
I
K
= 10mA, V
KA
= V
REF
,0.5%
CM431A
Min
2.482
2.478
2.470
O
Typ
2.495
2.495
2.495
4
-1.4
2
0.4
0.1
0.2
Max
2.507
2.512
2.520
17
-2.7
4
2.3
1
1
0.5
Units
V
V
V
mV
mV/V
µA
mA
µA
Ω
Reference Input Voltage
Reference Drift
Voltage Ratio, Ref to Cathode
(note 4)
Reference Input Current
Minimum Operating Current
Off-State Cathode Current
Dynamic Impedance
V
REF
I
K
= 10mA, V
KA
= V
REF
,0.7%
I
K
= 10mA, V
KA
= V
REF
,1.0%
I
K
= 10mA, V
KA
= V
REF
, 0 C
≤
T
A
≤
70 C
O
I
K
= 10mA, V
KA
= 2.5V to 18V
I
REF
I
MIN
I
OFF
|Z
KA
|
I
K
= 10mA,V
KA
= V
REF
I
K
= 10mA,V
KA
= V
REF
, 0
O
C
≤
T
A
≤
70
O
C
V
KA
= V
REF
V
KA
= 18V, V
REF
= 0V
V
KA
= V
REF
, I
K
= 1mA to 100mA,
f
≤
1kHz
Note 3: These parameters are guaranteed by design
Note 4:
V
REF
V
KA
Ratio of change in reference input voltage to the change in cathode voltage
2004/08/05
Preliminary
Champion Microelectronic Corporation
Page 5
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