Datasheet

Industrial V/I Converter and Protector IC
AM462
Analog Microelectronics GmbH
An der Fahrt 13, D – 55124 Mainz Oktober 2007 – Rev.2.5 -Page 16/20
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Fax: [phone]
Internet:
http://www.analogmicro.de
Email: info@analogmicro
.de
Using Equation (13) the following applies:
157.0
V456.3
V456.3V4
6
6
7
6
≈
−
=
∆
∆
−∆
=
PIN
PININ
V
VV
R
R
⇒
67
35.6 RR
⋅
=
According to Equation (14) the minimum output current generated by the input offset is calculated
as:
mA2
278
1
16.37
6,37
V5.0
8
1
076
7
minmin
≈
Ω⋅
⋅
+
⋅=⋅
+
⋅=
RRR
R
VI
INOUT
To obtain an output current of I
OUT
= 4...20mA, according to the above a current of I
SET
= 2mA must
then be added. With reference to Equation (5) the ratio of R
3
to R
4
is calculated thus:
43
4
0
!
2
mA2
RR
R
R
V
I
REF
SET
+
⋅==
⇒
3.451
mA2272
V5
1
2
04
3
≈−
⋅Ω⋅
=−=
SET
REF
IR
V
R
R
Observing the given boundary conditions, the following values are obtained for the external
components:
R
0
= 27Ω R
6
≈ 10kΩ R
7
= 63.7kΩ R
3
= 90.6kΩ R
4
= 2kΩ
R
5
= 39Ω R
L
= 0...600Ω C
1
= 2.2µF R
9
= 47 kΩ
Ground
R
5
R
L
1
Signal-ended
input voltage
Connections setting unused funktion blocks in a defined operating point
3-wire connection
V
BG
1
2
AM462
OP2
R
7
R
9
4
OP1
5
3
R
3
C
1
R
0
14
6
13
15
16
11
8
9
10
V
I
R
4
T
1
D
1
Voltage reference
V
S
I
OUT
R
6
V
IN
Figure 9: Converting an input signal with an input signal offset (3-wire-application)