am452 AME, Inc., am452 Datasheet - Page 13

• Manufacturer Part Number: am452
• Description: Voltage-to-current Transducer Ic With A Differential Input - Analog Microelectronics
• Manufacturer: AME, Inc.

The output current range (e.g. 16mA) is set by the selection of external resistors R
fine adjustment with R
If the offset of the AM452 signal source and input amplifier (IA) is such that it cannot be
ignored, when setting the output current range (gain)
must possibly be accounted for by making a fine adjustment to R
signal source and input amplifier is not relevant to the required degree of precision, Equations
(9) and (10) continue to apply.
OPERATING AM452: IMPORTANT POINTS TO NOTE
1. When using AM452 it is imperative that external capacitor C
2. All AM452 function blocks not required by the application (OP2 or VREF) must be
3. The voltages at the IA inputs (pins IN+ and IN-) must always lie within input voltage
4. At the current output a load resistance of 600 maximum is permissible for 3-wire
5. The values of external resistors R
6. The tolerances of the resistors and their temperature coefficients are entered into the
7. In order to avoid temperature gradients it is imperative that the transistor is placed far
8. In a 2-wire setup with a minimum output (offset) current of I
Analog Microelectronics GmbH
An der Fahrt 13, D – 55124 Mainz
always connected. Care must be taken that the value of the capacitor does not exceed the
range of values given in the boundary conditions – also within the temperature range (see
Table 2). In 2-wire operation ceramic capacitor C
placed in a defined (and allowed) operating state.
range CMIR.
operation.
the permissible range given in the boundary conditions.
overall error.
enough away from IC AM452 and that a sufficient temperature outlet is ensured.
(the total domestic power supply across a temperature range of < I
connected components (such as sensors) must be taken into account.
AM452 – Voltage-to-current transducer IC
I
I
OUT
OUT
V
V
IN
IN
0
G
with a differential input
). Output current I
0
I
R
G
0
VI
I
SET
I
SET
with
0
with
, R
I
SET
1
OUT
, R
G
I
2
is then calculated as:
, R
V
2
REF
R
G
3
0
, R
IA
R
2
4
G
, R
3
must also be used.
R
I
GAIN
4
OUT
5
R
, R
4
and
V
6
:
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February 2008 - Rev 1.2 - Page 13/21
IN
and R
V
R
R
3
ZA
0
OUT min
3
4
and R
1
7
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(a ceramic capacitor) is
also changes. This shift
OUT min
must be selected within
0
2
4
R
V
. If the offset of the
the current balance
0
REF
) of the IC and all
I
SET
1
and R
1
2
(10)
(9)
(or