Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw1
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 reference 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 voltage 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 output circuitry provides a very sharp turn-on
characteristic, making the APL1431 excellent replacements for zener diodes in many applications, including 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 , VO = V
REF
to 20V
••
••
• Low Operational Cathode Current , 250µA
Typical
••
••
• 0.1Ω 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
12
3
SOT-89 (Top View)
REFANODECATHODE
123
REF
ANODE
CATHODE
1
2
3
TO-92 (Top View)
CathodeAnode
REF
Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw2
Symbol Parameter Rating Unit
V
KA
Cathode voltage
20 V
I
K
Continuous cathode current range
120 mA
I
REF
Reference current range
3mA
θ
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, Ts (Soldering, 10sec)
260
°
C
Ordering and Marking Information
APL1431
Elec. Grade
Handling Code
Temp. Range
Package Code
Elec. Grade
A : 0.5% Reference Voltage Tolerance
B : 1% R eference Voltage Tolerance
Package Code
A : S O T -23 D : S O T-8 9 E : TO-92
Y : C hip Fo rm
Temp. Range
C : 0 to 70 C I : -40 to 85 C
Handling Code
PB : P lastic B ag TB : Tape & Box
TR : Ta pe & Reel
°
°
APL
1431
XXXXX
XXXXX - Date Code
APL1431 E :
APL1431 D :
APL1431
XXXXX
- Date Code
XXXXX
APL1431 A :
1431
Absolute Maximum Ratings
Electrical Characteristics
TA= 25°C ( 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=VREF
,
I
K
=10mA
*1
APL431B 2.475 2.500 2.525
V
∆
V
REF
/T
Reference voltage
drift over temp. range
V
KA=VREF
, IK=10mA
T
A
= 0 to 70°C
*1
TA= -40 to 85°C
*1
20
30
mV
IK=10mA, VKA=V
REF
to 10V
*2
-1.5 -3
∆
V
REF
/ ∆V
KA
Voltage ratio (open
loop gain)
I
K
=10mA, VKA=V
REF
to 20V
*2
-1.2 -2.5
mV/V
Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw3
Electrical Characteristics Cont. T
A
= 25°C ( unless otherwise noted)
Test figures
Figure 1. Test Circuit for VKA=V
REF
, VO=VKA=V
REF
Figure 2. Test Circuit for VKA>V
REF
,
VO= VKA= V
REF
× (1+R1/R2) + 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
Ω
0.1%
27.5k
Ω
0.1%
R
b
APL1431
Symbol Parameter Test Conditions
Min. Typ. Max.
Unit
I
REF
Reference current
I
K
=10mA,
R
1
=10kΩ, R2=open
*2
1.0 3
µ
A
∆
I
REF
/T
Reference current
drift
I
K
=10mA, R1=10kΩ,
R
2
=open, TA= -40 to 85°C
*2
0.3 1
µ
A
I
K(min)
Min. cathode current VKA=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
µ
A
|ZKA| Dynamic impedance
V
KA=VREF
IK=1mA to 100mA, f ≤1kHz
*1
0.1 0.4
Ω
I
K
Cathode current VKA=V
REF
+ 50mV
*2
100 mA
Copyright ANPEC Electronics Corp.
Rev. A.3 - May., 2003
APL1431
www.anpec.com.tw4
Typical Characteristics
Cathode Current -µA
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 -µA
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