TL431 Series
FIGURE 1-TEST CIRCUIT FOR V
KA
=
V
ref
Input
I
K
V
KA
FIGURE 3-TEST CIRCUIT FOR I
off
Input
I
off
V
KA
V
ref
FIGURE 2-TEST CIRCUIT FOR V
KA
>
V
ref
Input
I
K
R1
I
ref
V
KA
= V
ref
( 1+
R1
) + I
ref
R2
Example :
V
ref
= 8.0mV and slope is positive,
V
ref
at 25 =2.495V,
Ta=70
= 45.8 ppm/
V
KA
V
ref
=
R1
0.008
70
10
6
(2.495)
Note 2: The dynamic impedance Z
ka
is defined as:
|Z
ka
| =
VKA
Ik
R2
V
ref
When the device is programmed with two external
Note 1:
The deviation parameter
V
ref
is defined as the differences
between the maximum and minimum values obtained over the
full operating ambient temperature range that applies.
|Z
ka’
| = |Z
ka
| (1+
R1
R2
)
resistors, R1 and R2, (refer to Figure 2) the total
dynamic impedance of the circuit is defined as:
V
ref
Max.
V
ref
= V
ref (Max.)
-
V
ref
(Min.)
Ta = T
2
- T
1
V
ref
Min.
T1
T2
AMBIENT TEMPERATURE
The average temperature coefficient of the Reference
input voltage,
V
ref
, is defined as:
(
)=
V
ref
V
ref
at 25
Ta
V
ref
10
6
)
10
6
V
ref
(
ppm
=
Ta(V
ref
at 25 )
V
ref
can be positive or negative depending on whether
V
ref
Min. or V
ref
Max. occurs at the lower ambient temperature.
2008. 7. 3
Revision No : 0
3/6
KEC [ KEC(KOREA ELECTRONICS) ]
