am422 AME, Inc., am422 Datasheet - Page 10

• Manufacturer Part Number: am422
• Description: Voltage/current Converter - Analog Microelectronics
• Manufacturer: AME, Inc.

The information provided herein is believed to be reliable; however, Analog Microelectronics assumes no responsibility for inaccuracies or omissions. Analog Microelectronics assumes no responsibility
for the use of this information, and all use of such information shall be entirely at the user's own risk. Prices and specifications are subject to change without notice. No patent rights or licences to any of
the circuits described herein are implied or granted to any third party. Analog Microelectronics does not authorise or warrant any Analog Microelectronics product use in life support devices and/or
systems.
VOLTAGE/CURRENT CONVERTER
TYPICAL TWO–WIRE APPLICATION (0 – 1V)
Used in a two–wire circuit (AM422–2) ground pin 7 (GND, ⊥) is connected between R
load resistor (Figure 9). The relationship R
The current I
With R
Example 4: Output current range 4...20mA
In this case the values of the external devices (V
R
R
analog microelectronics
Figure 9
0
1
R
/R
V
= 25Ω
SET
IN
R
2
4
≈ 0.25
3
R
1
= R
R
2
V
SET
4
SET
the set resistor R
4
5
AM4222
is used to set the output current offset and can be calculated by using equation 3
I
R
R
R
V
SET
SET
1
2
REF
2
=
(
V
≈
2
IN
R
R
R I
4
3
L
0
R R I
=
= R
= 0...500Ω
(
0
Amplifier
V
0
G = 1
OUTmax
)
REF
V
SET
4
4
=
INmax
= 33kΩ
V
SET
becomes (equation 4)
R
REF
0
−
V
OFFSET
I
⋅
R
SET
7
2
3
(
(
R
R
)
4
1
3
/R
−
+
+
1
2
R
V
R
, using equation 2, becomes
5/10 V Reference
SET
R
C
4
IN
6
SET
1
+
= 0...1V) are as follows
= 2.2µF
)
R
−
≈ 2.64kΩ
SET
V
R
REF
3
)
8
I
C
1
1
2
3
R
C
5
2
= 40Ω
= 100nF
T
1
D
R
1
0
R
5
AM422
C
2
I
OUT
V
5
R
Ground
S
L
and the
April 99
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