AIC431/TL431A/TL431
n
ELECTRICAL CHARACTERISTICS
(Continued)
PARAMETER
Minimum Cathode current for
Regulation
Off-State Current
Dynamic Output Impedance
(Note 4)
TEST CONDITIONS
V
Z
=V
REF
(Fig. 1)
V
Z
=20V, V
REF
=0V (Fig. 3)
V
Z
=V
REF
Frequency= 0Hz (Fig. 1)
SYMBOL
MIN.
TYP.
0.25
0.1
0.08
MAX.
0.5
1.0
0.3
UNIT
mA
µA
Ω
I
Z(MIN)
I
Z(OFF)
R
Z
V
MAX
V
DEV
= V
MAX
-V
MIN
V
MIN
Where:
T
2
−
T
1
=full temperature change.
αV
REF
can be positive or negative depending on
whether the slope is positive or negative.
Example: V
DEV
= 9.0mV, V
REF
= 2495mV,
T
2
−
T
1
= 70°C, slope is negative.
α
V
REF
T
1
TEMPERATURE
T
2
9.0mV
106
2495mV
=
= −
50ppm/
°
C
70
°
C
Note 3.
Deviation of reference input voltage, V
DEV
, is de-
fined as the maximum variation of the reference input
voltage over the full temperature range.
The average temperature coefficient of the reference in-
put voltage,
αV
REF
is d efined as:
V
MAX
- V
MIN
6
6
V
DEV
±
±
10
10
ppm
V
REF
(at 25
°
C)
V
REF
(at 25
°
C)
∆
V
REF
=
=
°
C
T2
−
T1
T2
−
T1
Note 4.
The dynamic output impedance, Rz, is de-
fined as:
R
Z
=
∆
V
Z
∆
I
Z
When the device is programmed with two external re-
sistors, R1 and R2, (see Fig. 2), the dynamic output
impedance of the overall circuit, is defined as:
r
z
=
∆
Vz
R1
≅
Rz
1
+
R2
∆
Iz
[ ]
n
TYPICAL
1000
800
600
400
200
0
-200
-400
PERFORMANCE CHARACTERISTICS
Reference Voltage vs Temperature
2.58
2.56
Cathode Current vs Cathode Voltage
V
Z
=V
REF
T
A
=25
°
C
V
Z
=V
REF
I
Z
=10mA
V
REF
=2.535V
Reference Voltage (V)
I
Z(MIN)
Cathode Current (µA)
2.54
2.52
2.50
2.48
2.46
2.44
2.42
V
REF
=2.495V
V
REF
=2.455V
-20
0
20
40
60
80
100
120
-600
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
2.40
-40
Cathode Voltage (V)
Temperature (
°
C )
5
AIC [ ANALOG INTERGRATIONS CORPORATION ]
