AMS431L
TEST CIRCUITS
V
Z
= V
REF
V
Z
V
Z
V
IN
V
IN
V
IN
I
REF
I
Z
V
REF
R1
I
REF
I
Z
I
Z
OFF
R2
V
REF
Figure 1.
Test Circuit for V
Z
=V
REF
Figure 2.
Test Circuit for V
REF
vs I
Z
.
Test circuit for I
REF
.
Figure 3.
Test Circuit for Off-State Current
TYPICAL APPLICATIONS
V
IN
R1
V
REF
R2
GND
V
OUT
1) Set the V
OUT
according to the following equation:
R1
V
OUT
=
V
REF
1
+
+
I
REF
R1
R2
2) Choose the value of R as follows:
•
•
The maximum limit for R should be such that the cathode current, I
Z
is greater than the minimum operating current (80µA) at V
IN(min)
.
The minimum limit for R should b such that I
Z
does not exceed 100mA under all load conditions, and the instantaneous turn-on value for I
Z
does not exceed
150mA. Both of the following conditions must be met:
V
IN(max)
(
to limit instantane ous turn - on I
Z
)
150mA
R
min
≥
R
min
≥
V
IN(max)
- V
OUT
(
to limit I
Z
under normal operating conditions
)
I
OUT(min)
+
100mA
3
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AMS [ Advanced Monolithic Systems Ltd ]
