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 7/20
Phone: [phone]
Fax: [phone]
Internet:
http://www.analogmicro.de
Email: info@analogmicro
.de
SET
IVINDAI
OUT
I
R
GV
I +
⋅
=
0
=
SET
INDAI
I
R
V
+
0
8
with
02R
V
I
SET
SET
=
(2)
with V
INDAI
the voltage at pin 6 (INDAI) and V
SET
the voltage at pin 16 (SET)
1
.
3. The AM462 reference voltage source enables voltage to be supplied to external components
(such as sensors, microprocessors, etc.). The reference voltage value V
REF
can be set via pin 13
VSET. If pin VSET is not connected, V
REF
= 5V; if VSET is switched to ground, V
REF
= 10V.
Values between the above can be set if two external resistors are used (inserted between pin
VREF and pin VSET and between pin VSET and GND; see Figure 2).
External (ceramic) capacitor C
1
at pin VREF stabilizes the reference voltage. It must be
connected even if the voltage reference is not in use.
4. The additional operational amplifier stage OP2 can be used as a current or voltage source to
supply external components. OP2's positive input is connected internally to voltage V
BG
so that
the output current or output voltage can be set across a wide range using external resistors.
1
The construction of the V/I converter is such that output current I
OUT
is largely independent of the current
amplification
β
F
of external transistor T
1
. Production-specific variations in the current amplification of the transistors
used are compensated for internally by the V/I converter.
V
BG
Ground
V
S
I
OUT
R
1
R
2
R
0
T
1
D
1
R
5
V
INP
V
SET
V
OUTAD
V
CVREF
V
CVSET
R
4
V
BG
4
11
10
8
OP1
5
2
AM462
OP2
3
C
1
V
REF
R
3
13
15
Volt age Ref er ence
1
16
9
V
INDAI
14
V
I
6
Figure 2: Block diagram of AM462 (3-wire circuit for current output). Pin 1 and 2
have to be connected.