Datasheet

VOLTAGE/CURRENT CONVERTER AM422
analog microelectronics
April 99
3/10
Parameter Symbol Conditions Min. Typ. Max. Unit
V/I Converter
Internal Gain G
VI
1.00
Trim Range adjustable by R
0
0.75 1.00 1.25
Voltage Range at R
0
FS V
R0
FS 400 500 580 mV
Offset Voltage V
OS
β
F
≥ 100
±2 ±6mV
V
OS
vs. Temperature dV
OS
/dT
β
F
≥ 100
±7 ±20 µV/°C
Output Offset Current I
OUTOS
3–wire operation –35 –50 µA
I
OUTOS
vs. Temperature dI
OUTOS
/dT 3–wire operation 55 80 nA/°C
Output Offset Current I
OUTOS
2–wire operation 14 22 µA
I
OUTOS
vs. Temperature dI
OUTOS
/dT 2–wire operation 22 35 nA/°C
Output Control Current I
OUTC
2–wire operation, V
R
0
/100mV 5 µA
I
OUTC
vs. Temperature dI
OUTC
/dT 2–wire operation –9 nA/°C
Output Voltage Range V
OUT
V
OUT
= R
L
I
OUT
, V
CC
< 16V 0 V
CC
– 6 V
V
OUT
V
OUT
=
R
L
I
OUT
,
V
CC
≥ 16V
010V
Output Current Range FS
I
OUTFS
I
OUT
=
V
R0
/R
0
, 3–wire operation 20 mA
Output Resistance R
OUT
0.5 1.0
MΩ
Load Capacitance C
L
0 500 nF
Protection Functions
Voltage Limitation at R
0
V
LIMR0
V
R0
= V
IN
/2, SET = V
REF
/2 580 635 690 mV
V
LIMR0
V
IN
= 0, V
R0
= V
SET
/2 – V
REF
/2 580 640 700 mV
Temperature Limitation T
LIMIT
110 130 150 °C
Protection against reverse polarity Ground vs. V
S
vs. I
OUT
35 V
Current in case of reverse polarity
Ground
= 35V,
V
S
=
I
OUT
= 0 3.8 mA
System Parameters
Nonlinearity ideal input 0.05 0.15 %FS
* In 2–wire operation a maximum current of I
OUTmin
– I
CC
is valid
Currents flowing into the IC are negative
BOUNDARY CONDITIONS
Parameter Symbol Conditions Min. Typ. Max. Unit
Sense Resistor R
0
I
OUTFS
= 20mA 202529
Ω
R
0
c = 20mA/I
OUTFS
c ⋅ 20 c ⋅ 25 c ⋅ 29 Ω
Stabilisation Resistor
R
5
I
OUTFS
= 20mA 354045
Ω
R
5
c
= 20mA/
I
OUTFS
c ⋅ 35 c ⋅ 40 c ⋅ 45 Ω
Load Resistance R
L
limitation only for 3–wire operation 0 500
Ω
Sum Offset Resistors R
3
+ R
4
20 200
kΩ
V
REF
Capacitance C
1
1.9 2.2 5.0
µF
Output Capacitance
C
2
only for 2–wire operation 90 100 250 nF
D
1
Breakdown Voltage V
BR
35 50 V
T
1
Forward Current Gain
β
F
50 150