SPX431A,B,C
Precision Adjustable Shunt Regulator
FEATURES
• Trimmed Bandgap: 0.5%, 1% and 2%
• Wide Operating Current: 1mA to 150mA
• Extended Temperature Range:
0°C to 105°C
• Low Temperature Coefficient: 30 ppm/°C
• Improved Replacement in Performance
for TL43
• Low Cost Solution
• Available in Lead Free, RoHS compliant
packaging: SOIC, SOT-89, SOT-23-3,
SOT-23-5, and TO-92
APPLICATIONS
• Battery Operated Equipment
• Adjustable Supplies
• Switching Power Supplies
• Error Amplifiers
• Single Supply Amplifier
• Monitors/VCRs/TVs
• Personal Computers
DESCRIPTION
The SPX43 is a three-terminal adjustable shunt voltage regulator providing a highly accurate
bandgap reference. The SPX431 acts as an open-loop error amplifier with a 2.5V temperature
compensation reference. The SPX431 has thermal stability, wide operating current of 150mA
and broad temperature range of 0°C
to 150°C, making it suitable for a variety of applications
which require a low-cost, high performance solution. SPX431A tolerance of 0.5% is proven
to be sufficient to overcome all other errors in the system to virtually eliminate the need for
trimming in the power supply manufacturer's assembly line and contribute a significant cost
savings. The output voltage may be adjusted to any value between V
REF
and 36 volts with
two external resistors. The SPX431 is available in SOIC-8, SOT-23-3, SOT-23-5, SOT89,
and TO-92 packages.
TyPICAL APPLICATIONS CIRCUIT
Cathode (K)
Reference
(R)
+
-
2.5V
Anode (A)
Rev F: Nov 2-06
SPX43A,B,C Precision Adjustable Shunt Regulator
© 2006 Sipex Corporation
ABSOLUTE mAXImUm RATINGS
Cathode-Anode Reverse Breakdown V
ka
......................................37V
Anode-Cathode Forward Current, (<10ms) I
ak
................................A
Operating Cathode Current I
ka
..................................................150mA
Reference Input Current I
ref
......................................................0mA
Continuous Power Dissipation at 25°C P
d
SOIC-8
.....................................................................750mW
SOT-23-5
................................................................200 mW
SOT-23-3
................................................................47 mW
SOT-89
..................................................................000mW\
TO-92
.......................................................................775mW
Junction Temperature T
j
...........................................................
150 °C
Storage Temperature T
stg
...............................................-65
to 150 °C
NOTE:
Stresses greater than those listed under ABSOLUTE MAXIMUM
RATINGS may cause permanent damage to the device. This is a stress
rating only and functional operation of the device at these or any other
conditions above those indicated in the operational sections of this speci-
fication is not implied. Exposure to absolute maximum rating conditions
for extended periods may affect reliability.
RECOmmENDED CONDITIONS
PARAmETER
SymBOL
Cathode Voltage
V
KA
Cathode Current
I
K
RATING
V
REF
to 36
0
UNIT
V
mA
TyPICAL ThERmAL RESISTANCES
PACKAGE
SOIC-8
TO-92
SOT-89
Ø
JA
Ø
JC
TyPICAL DERATING
5.7 mW/°C
6.3 mW/°C
9.1 mW/°C
1.7 mW/°C
3.3 mW/°C
124.8°C/W 45°C/W
131.9°C/W 80°C/W
107.1°C/W
8°C/W
SOT-23-5 191°C/W 150°C/W
SOT-23-3 300°C/W 136°C/W
Typical deratings of the thermal resistances are given for ambient
temperature >25°.
ELECTRICAL ChARACTERISTICS
Parameter
Symbol
Test
Conditions
Electrical characteristics at 25°C I
k
= 10mA V
k
= V
ref
, unless otherwise specified.
Test
Circuit
min
Reference Voltage
V
REF
TC
∆V
ref
∆V
k
I
REF
∆I
REF
I
K(MIN)
I
K(OFF)
Z
KA
V
REF
= 0V,
V
KA
= 36V
f
Z
= 1kHz
I
K
= 1 to 150mA
T
J
= 0°C to
105°C
V
REF
to 10V
10V to 36V
T
J
= 0°C to
105°C
-2.7
-2
SPX431A
Typ
max
min
SPX431B
Typ
max
min
SPX431C
Typ
max
2.545
V
V
mV/
°C
mV/
V
µA
µA
mA
nA
Ω
Unit
2.490
2.515
2.470
2.520
2.503
2.495
2.445 2.495
2.469
2.536 2.449
2.541
0.07
-.0
-0.4
0.7
0.4
0.4
0.04
0.15
0.20
-2.7
-2.0
0.07
-.0
-0.4
0.7
0.4
0.4
0.04
0.15
0.20
-2.7
-2
0.07
-.0
-0.4
0.7
0.4
0.4
0.04
0.15
∆V
REF
with Temp.
Ratio of Change
in V
REF
to Cath-
ode Voltage
Reference Input
Current
I
REF
Temp
Deviation
Min I
K
for
Regulation
Off State Leak-
age
Dynamic Output
Impedance
0.20
2
2
2
0.3
4
.2
250
0.5
0.3
4
.2
500
0.5
0.3
4
.2
000
0.5
3
Rev F: Nov 2-06
SPX43A,B,C Precision Adjustable Shunt Regulator
© 2006 Sipex Corporation
2
CALCULATING AvERAGE TEmPERATURE COEFFICIENT (TC)
ppm/°C
0
%/°C
0
mV/°C
0
DV
REF
D
TC in mV/°C =
DV
REF
(mV)
DT
A
-10
5000
0.5
TC in % /°C =
(
DV
REF
DV
REF
at 25°C
DT
A
)
x 100
0
15
30
45
60
75
90
105
TC in ppm/°C =
(
DV
REF
DV
REF
at 25°C
DT
A
)
x 10
6
Junction Temperature (°C)
0.07 mV/°C
0.003 %/°C
27 ppm/°C
Figure 1. V
ref
VS Temperature.
PACKAGE PINOUTS
8-Pin Surface Mount (S)
CATHODE
ANODE
ANODE
N/C
1
2
3
4
8
7
REF
ANODE
ANODE
N/C
SOT-23-5 (M5)
REF
5
4
2
3
SOT-89 (M1)
ANODE
TO-92 (N)
1
2
3
SOT-23-3 (M)
ANODE
3
SPX431
SPX431
1
SPX431
1
2
3
REF
ANODE
CATHODE
1
6
5
SPX431
2
N/C N/C CATHODE
REF ANODE CATHODE
CATHODE
REF
Top View
Top View
Top View
Bottom View
Top View
TEST CIRCUITS
V
IN
V
KA =
V
REF
V
IN
V
KA
V
IN
V
KA
I
K (OFF)
I
REF
I
K
R1
(V
REF
)
R2
I
REF
I
K
Test Circuit .
Test Circuit for V
ka
= V
ref
Test Circuit 2.
Test Circuit for V
ka
> V
ref
Test Circuit 3.
Test Circuit for I
koff
Rev F: Nov 2-06
SPX43A,B,C Precision Adjustable Shunt Regulator
© 2006 Sipex Corporation
3
TyPICAL PERFORmANCE ChARACTERISTICS
150
125
100
2.53
V
KA
= V
REF
Temperature Range: 0°C to 105°C
2.52
V
REF
Reference Voltage (V)
2.51
2.50
2.49
2.48
2.47
2.46
2.45
-60
V
KA
= V
REF
I
K
= 10mA
I
K
- Cathode Current (mA)
75
50
25
0
-25
-50
-75
-100
-2
-1
0
1
2
3
V
KA
- Cathode Voltage (V)
-30
0
30
60
90
T
A
Ambient Temperature (°C)
120
High Current Operating Characteristics
Reference Voltage vs. Ambient Temperature
900
V
KA
= V
REF
0° to 105°C
3.0
I
REF
Reference Input Current (µA)
800
700
2.5
2.0
1.5
1.0
0.5
0
-60
R1 = 10kΩ
R2 = ∞
I
K
= 10mA
I
K
Cathode Current (µA)
600
500
400
300
200
100
0
-100
-200
-1.0
1.0
2.0
V
KA
Cathode Voltage (V)
0
3.0
105°C
25°C
-0°C
-30
0
30
60
90
T
A
Ambient Temperature (°C)
120
Low Current Operating Characteristics
Reference Input Current vs. Ambient Temperature
0
70
60
0°C
Noise Voltage nV/÷Hz
-10
50
40
30
20
10
0
V
KA
= V
REF
I
K
= 10mA
T
A
= 25°C
∆V
REF
(mV)
-20
25°C
75°C
-30
I
KA
= 10mA
-40
125°C
-50
0
3
6
9
12 15
18
21
24
27 30
V
KA
Cathode Voltage (V)
f Frequency (Hz)
Reference Voltage Line Regulation vs, Cathode Volt-
age and T
ambient
Rev F: Nov 2-06
Noise Voltage vs. Frequency
SPX43A,B,C Precision Adjustable Shunt Regulator
© 2006 Sipex Corporation
4
TyPICAL PERFORmANCE ChARACTERISTICS (continued)
0.150
0.125
0.100
0.075
0.050
0.025
0.0
-60
-30
0
30
60
90
T
A
Free Air Temperature
120
V
KA
= V
REF
I
K
= 1 to 100mA
f≤1kHz
60dB
50dB
40dB
30dB
20dB
10dB
0dB
-10dB
-20dB
-30dB
-40dB
10
GAIN
PHASE
REF LEVEL
60.000dB
0.0deg
/DIV
10.000dB
45.000deg
MARKER 19 422
611.000Hz
MAG (A/R)
-0.125dB
MARKER 19 422
611.000Hz
PHASE (A/R)
46.717deg
215°
180°
135°
90°
45°
0°
-45°
-90°
-135°
-180°
-215°
100
1K
10K
100K
1M
10M
START 10.000Hz
STOP 50 000 000.000Hz
Low Frequency Dynamic Output Impedance vs.
T
ambient
Small Signal Gain and Phase vs. Frequency; I
k
=
0mA, T
a
= 25°C
V
OUT
15kΩ
230Ω
V
IN
9µF
I
K
V
OUT
V
IN
8.25kΩ
GND
Test Circuit for Gain and Phase Frequency Re-
sponse
F
z
= 100kHz, I
k
= 0mA, T
a
= 25°C
V
IN
250Ω
I
K
Cathode Current (mA)
100
90
A: V
KA
= V
REF
B: V
KA
= 5V at I
K
=10mA
C: V
KA
=10V at I
K
=10mA
D: V
KA
=15V at I
K
=10mA
C
V
OUT
I
K
f
p = 100kHz
50Ω
80
70
60
50
40
STABLE
30
20
10
0
10
0
T
A = 25°C
B
A
STABLE
D
10
1
10
2
10
3
10
4
10
5
10
6
10
7
GND
Test Circuit for Pulse Response
C
L
Load Capacitance (pF)
Stability Boundry Conditions
Rev F: Nov 2-06
SPX43A,B,C Precision Adjustable Shunt Regulator
© 2006 Sipex Corporation
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