Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw
1
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise
customers to obtain the latest version of relevant information to verify before placing orders.
Adjustable Precision Shunt Regulator
Features
General Description
Applications
The APL1431 is a 3-terminal adjustable voltage ref-
erence with specified thermal stability over applicable
commercial temperature ranges. Output voltage may
be set to any value between V
ref
(2.5 V) and 20 V with
two external resistors (see Figure 2). When used
with an photocoupler, the APL1431 is an ideal volt-
age reference in isolated feedback circuits for 2.5V
to 12V switching-mode power supplies. This device
has a typical output impedance of 0.1
. Active out-
put circuitry provides a very sharp turn-on
characteristic,
making the APL1431 excellent replace-
ments for zener diodes in many applications, includ-
ing on-board regulation and adjustable power
supplies.
Precise Reference Voltage to 2.500V
Guaranteed 0.5% or 1% Reference Voltage
Tolerance
Sink Current Capability , 1mA to 100mA
Quick Turn-on
Adjustable Output Voltage , V
O
= V
REF
to 20V
Low Operational Cathode Current , 250A
Typical
0.1
Typical Output Impedance
SOT-23 , SOT-89 and TO-92 Packages
Linear Regulators
Adjustable Power Supply
Switching Power Supply
Symbol
Functional Diagram
V
ref
+
_
Cathode
REF
Anode
SOT-23 (Top View)
REF
ANODE
CATHODE
1
2
3
SOT-89 (Top View)
REF
ANODE
CATHODE
1
2
3
REF
ANODE
CATHO DE
1
2
3
TO-92 (Top View)
Cathode
Anode
REF
Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw
2
Symbol
Parameter
Rating
Unit
V
KA
Cathode voltage
20
V
I
K
Continuous cathode current range
120
mA
I
REF
Reference current range
3
mA
JA
Thermal Resistance from Junction to Ambient in Free Air
SOT-23
SOT-89
TO-92
416
250
250
C/W
T
A
Ambient temperature range APL1431XXC
APL1431XXI
0 to 70
-40 to 85
C
T
j
Junction temperature range APL1431XXC
APL1431XXI
0 to 150
-40 to 150
C
T
STG
Storage Temperature Range
-65 to 150
C
T
SOL
Lead temperature range, T
s
(Soldering, 10sec)
260
C
Ordering and Marking Information
A P L 1 4 3 1
E le c . G ra d e
H a n d lin g C o d e
T e m p . R a n g e
P a c k a g e C o d e
E le c . G ra d e
A : 0 .5 % R e fe re n c e V o lta g e T o le ra n c e
B : 1 % R e fe re n c e V o lta g e T o le ra n c e
P a c k a g e C o d e
A : S O T -2 3 D : S O T -8 9 E : T O -9 2
Y : C h ip F o rm
T e m p . R a n g e
C : 0 to 7 0 C
I : -4 0 to 8 5 C
H a n d lin g C o d e
P B : P la s tic B a g T B : T a p e & B o x
T R : T a p e & R e e l
A P L
1 4 3 1
X X X X X
X X X X X - D a te C o d e
A P L 1 4 3 1 E :
A P L 1 4 3 1 D :
A P L 1 4 3 1
X X X X X
- D a te C o d e
X X X X X
A P L 1 4 3 1 A :
1 4 3 1
Absolute Maximum Ratings
Electrical Characteristics
T
A
= 25C ( unless otherwise noted)
APL1431
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
APL431A 2.487
2.500
2.513
V
REF
Reference voltage
V
KA
=V
REF
,
I
K
=10mA
*1
APL431B 2.475
2.500
2.525
V
V
REF
/T
Reference voltage
drift over temp. range
V
KA
=V
REF
, I
K
=10mA
T
A
= 0 to 70
C
*1
T
A
= -40 to 85
C
*1
20
30
mV
I
K
=10mA, V
KA
=V
REF
to 10V
*2
-1.5
-3
V
REF
/
V
KA
Voltage ratio (open
loop gain)
I
K
=10mA, V
KA
=V
REF
to 20V
*2
-1.2
-2.5
mV/V
Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw
3
Electrical Characteristics Cont.
T
A
= 25C ( unless otherwise noted)
Test figures
Figure 1. Test Circuit for V
KA
=V
REF
, V
O
=V
KA
=V
REF
Figure 2. Test Circuit for V
KA
>V
REF
,
V
O
= V
KA
= V
REF
(1+R
1
/R
2
) + I
REF
R
1
Figure 3. Test Circuit for I
K(off)
Notes :
*1 : use Figure 1
*2 : use Figure 2
*3 : use Figure 3
Application schematic
R
b
should provide cathode current large than
1mA to maintain APL431 work properly.
5-Volt Precision Regulator
V
IN
V
o
I
K
V
REF
V
o
V
IN
I
K(off)
V
IN
I
K
I
REF
V
REF
R1
R2
V
o
V
o
V
IN
27.5k
0.1%
27.5k
0.1%
R
b
APL1431
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
I
REF
Reference current
I
K
=10mA,
R
1
=10k
, R
2
=open
*2
1.0
3
A
I
REF
/T
Reference current
drift
I
K
=10mA, R
1
=10k
,
R
2
=open, T
A
= -40 to 85
C
*2
0.3
1
A
I
K(min)
Min. cathode current V
KA
=V
REF
*1
0.25
0.5
mA
I
K(off)
Off-state cathode
current
V
KA
= 20V, V
REF
= 0V
*3
0.1
1
A
|Z
KA
|
Dynamic impedance
V
KA
=V
REF
I
K
=1mA to 100mA, f
1kHz
*1
0.1
0.4
I
K
Cathode current
V
KA
=V
REF
+ 50mV
*2
100
mA
Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw
4
Typical Characteristics
Cathode Current -
A
0
-200
200
400
600
800
-1
0
1
2
3
Cathode Voltage (V)
I
K-MIN
Cathode Current vs. Cathode Voltage
100
50
75
100
125
-40
-20
0
20
40
60
80
Reference Current -
A
Reference Current vs.Temperature
Temperature - C
Temperature ( C)
Reference Voltage vs. Temperature
2.47
2.475
2.48
2.485
2.49
2.495
2.5
2.505
2.51
2.515
2.52
-20
0
20
40
60
80
100
-40
Reference Voltage -V
-100
-50
0
50
100
-1
0
1
2
3
Cathode Current vs. Cathode Voltage
Cathode Current -mA
Cathode Voltage -V
Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw
5
Typical Characteristics (Cont.)
0
10
20
30
40
50
60
1
10
100
1000
Small-Signal Voltage Amplification vs Frequency
Small-Signal Voltage Amplification- dB
Frequency - kHz
3
4
5
6
7
8
9
10 11 12 13
0
1
2
3
4
5
6
Pulse Response
Time -
s
Input and Output Voltage - V
Input
output
Temperature ( C)
-40
-20
0
20
40
60
80
100
0
0.1
0.2
0.3
0.4
0.5
V
KA
= 20V
V
REF
= 0
Off-State Cathode Current -
A
Off-State Cathode Current vsTemperature
Temperature ( C)
-40 -20
0
20
40 60
80
100 120
-2
-1.75
-1.5
-1.25
-1
-0.75
-0.5
-0.25
0
V
KA
= V
REF
to 20V
I
K
= 10mA
Ratio of Delta Reference Voltage to
Delta Cathode Voltage vs Temperature
Ratio of Delta Reference Voltage to
Delta Cathode Voltage - mV/V
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