WS
TL431
Note: 1. The deviation parameters V
REF(dev)
and I
REF(dev)
are defined as the differences between the maximum and minimum
values obtained over the rated temperature range.
V
REF(dev)
= V
REF
(max) - V
REF
(min)
The equivalent full-range temperature coefficient of the reference input voltage,
αV
REF
is defined as:
ppm
αV
REF
(
°
C
)
=
(
V
R EF(dev)
V
R EF
@
°
C
∆
Ta
)
×
10
6
where
∆Ta
is the rated operating free-air temperature range of the device.
αV
REF
can be positive or negative depending on whether minimum
V
REF
or maximum V
REF
respectively, occurs at the lower temperature.
2.
The dynamic impedance is defined as:
Z
K A
=
∆
V
KA
∆
I
K
When the device is operated with two external resistors (see Figure 2), the total dynamic impedance of the circuit is
given by:
Z
'
=
∆
V
∆
I
=
Z
K A
(1+
R
1
R
2
)
TEST CIRCUITS
Fig.1. Test Circuit for V
KA
= V
REF
Fig.2. Test Circuit for V
KA
≥
V
REF
Fig.3. Test Circuit for I
off
4-3
WINGS [ WING SHING COMPUTER COMPONENTS ]
