APL1431
Adjustable Precision Shunt Regulator
Features
•
•
•
•
•
•
•
•
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 , 250µA
Typical
0.1Ω Typical Output Impedance
SOT-23 , SOT-89 and TO-92 Packages
General Description
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 0.1Ω. 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.
ANODE
Applications
•
•
•
Linear Regulators
Adjustable Power Supply
Switching Power Supply
3
1
2
CATHODE REF
SOT-23 (Top View)
Symbol
REF
Anode
Cathode
1
2
3
CATHODE
ANODE
REF
Functional Diagram
C athode
SOT-89 (Top View)
1
REF
2
ANOD E
REF
+
_
3
CATHO DE
V
ref
TO-92 (Top View)
Anode
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.
Copyright
ANPEC Electronics Corp.
Rev. A.3 - May., 2003
1
www.anpec.com.tw
APL1431
Ordering and Marking Information
APL1431
L e a d F re e C o d e
H a n d lin g C o d e
Tem p. R ange
P ackage C ode
E le c . G ra 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 ackage C ode
A : S O T -2 3
D : S O T -8 9
E : T O -9 2
Y : C h ip F o rm
Tem p. R ange
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
TB : Tape & B ox
TR : Tape & R eel
L e a d F re e C o d e
L : L e a d F re e D e v ic e
B la n k : O rig in a l D e v ic e
APL
1431
XXXXX
A P L1431 A :
1431
A P L1431 E :
X X X X X - D a te C o d e
A P L1431 D :
A P L1431
XXXXX
XXXXX
- D a te C o d e
Absolute Maximum Ratings
Symbol
V
KA
I
K
I
REF
θ
JA
Parameter
Cathode voltage
Continuous cathode current range
Reference current range
Thermal Resistance from Junction to Ambient in Free Air
SOT-23
SOT-89
TO-92
Ambient temperature range
APL1431XXC
APL1431XXI
Junction temperature range
APL1431XXC
APL1431XXI
Storage Temperature Range
Lead temperature range, T
s
(Soldering, 10sec)
Rating
20
120
3
416
250
250
0 to 70
-40 to 85
0 to 150
-40 to 150
-65 to 150
260
Unit
V
mA
mA
°C/W
T
A
T
j
T
STG
T
SOL
°C
°C
°C
°C
Electrical Characteristics
Symbol
V
REF
∆V
REF
/T
∆V
REF
/
∆V
KA
Parameter
T
A
= 25°C ( unless otherwise noted)
Test Conditions
Unit
V
APL1431
Min.
Typ.
Max.
APL431A 2.487
2.500
2.513
V
KA
=V
REF
,
Reference voltage
*1
I
K
=10mA
APL431B 2.475
2.500
2.525
V
KA
=V
REF
, I
K
=10mA
Reference voltage
T = 0 to 70°C
*1
20
drift over temp. range
A
30
T
A
= -40 to 85°C
*1
I
K
=10mA, V
KA
=V
REF
to 10V
*2
-1.5
-3
Voltage ratio (open
loop gain)
I
K
=10mA, V
KA
=V
REF
to 20V
*2
-1.2
-2.5
2
mV
mV/V
Copyright
ANPEC Electronics Corp.
Rev. A.3 - May., 2003
www.anpec.com.tw
APL1431
Electrical Characteristics Cont.
Symbol
I
REF
∆I
REF
/T
I
K(min)
I
K(off)
|Z
KA
|
I
K
Parameter
Reference current
Reference current
drift
Min. cathode current
Off-state cathode
current
Dynamic impedance
Cathode current
T
A
= 25°C ( unless otherwise noted)
APL1431
Test Conditions
Min.
I
K
=10mA,
R
1
=10kΩ, R
2
=open
*2
I
K
=10mA, R
1
=10kΩ,
R
2
=open, T
A
= -40 to 85°C
*2
V
KA
=V
REF*1
V
KA
= 20V, V
REF
= 0V
*3
V
KA
=V
REF
I
K
=1mA to 100mA, f
≤1kHz
*1
V
KA
=V
REF
+ 50mV
*2
Typ.
1.0
0.3
0.25
0.1
0.1
Max.
3
1
0.5
1
0.4
100
Unit
µA
µA
mA
µA
Ω
mA
Notes :
*1 : use Figure 1
*2 : use Figure 2
*3 : use Figure 3
Test figures
V
IN
I
K
V
REF
V
o
V
IN
I
K(off)
V
o
Figure 1. Test Circuit for V
KA
=V
REF
, V
O
=V
KA
=V
REF
Figure 3. Test Circuit for I
K(off)
Application schematic
V
IN
I
K
R1
I
REF
V
REF
27.5kΩ
0.1%
V
o
V
IN
5-Volt Precision Regulator
V
o
R
b
27.5kΩ
0.1%
R2
Figure 2. Test Circuit for V
KA
>V
REF
,
V
O
= V
KA
= V
REF
×
(1+R
1
/R
2
) + I
REF
×
R
1
∗
R
b
should provide cathode current large than
1mA to maintain APL431 work properly.
Copyright
ANPEC Electronics Corp.
Rev. A.3 - May., 2003
3
www.anpec.com.tw
APL1431
Typical Characteristics
Reference Current vs.Temperature
125
800
Cathode Current vs. Cathode Voltage
600
Reference Current -µA
100
Cathode Current -µA
400
I
K-MIN
200
75
0
50-40
-20
0
20
40
60
80
100
-200
-1
0
1
2
3
Temperature -
°
C
Cathode Voltage (V)
Cathode Current vs. Cathode Voltage
100
2.52
2.515
2.51
Cathode Current -mA
Reference Voltage -V
50
2.505
2.5
2.495
2.49
2.485
2.48
2.475
-100
-1
0
1
2
3
Reference Voltage vs. Temperature
0
-50
2.47
-40
-20
0
20
40
60
80
100
Cathode Voltage -V
Temperature (
°
C)
Copyright
ANPEC Electronics Corp.
Rev. A.3 - May., 2003
4
www.anpec.com.tw
APL1431
Typical Characteristics (Cont.)
Small-Signal Voltage Amplification vs Frequency
60
Small-Signal Voltage Amplification- dB
6
Input
5
Input and Output Voltage - V
Pulse Response
50
40
30
20
10
4
output
3
2
1
0
3
0
1
10
100
1000
4
5
6
7
8
9
10 11 12 13
Frequency - kHz
Time -
µs
Off-State Cathode Current vsTemperature
0.5
Off-State Cathode Current -
µA
V
KA
= 20V
V
REF
= 0
Ratio of Delta Reference Voltage to
Delta Cathode Voltage vs Temperature
0
-0.25
Ratio of Delta Reference Voltage to
Delta Cathode Voltage - mV/V
-0.5
-0.75
-1
-1.25
-1.5
-1.75
-2
-40
-20
0
20
40
60
80
100 120
V
KA
= V
REF
to 20V
I
K
= 10mA
0.4
0.3
0.2
0.1
0
-40
-20
0
20
40
60
80
100
Temperature (
°
C)
Temperature (
°
C)
Copyright
ANPEC Electronics Corp.
Rev. A.3 - May., 2003
5
www.anpec.com.tw
