Datasheet

Industrial Converter and Protector IC AM460
analog microelectronics
April 2003
6/18
Parameter Symbol Conditions Min. Typ. Max. Unit
SET Stage
Internal Gain G
SET
0.5
Input Voltage V
SET
01.15V
Offset Voltage V
OS
±
0.5
±
1.5 mV
V
OS
vs. Temperature dV
OS
/dT
±
1.6
±
5µV/°C
Input Bias Current I
B
820nA
I
B
vs. Temperature dI
B
/dT 718pA/°C
Protection Functions
Voltage Limitation at R
0
V
LIMR0
V
R0
= V
INDAI
G
VI
, SET = GND 580 635 690 mV
V
LIMR0
V
INDAI
= 0, V
R0
= G
SET
V
SET
580 635 690 mV
Protection against reverse polarity Ground vs. V
S
vs. V
OUT
35 V
Ground vs. V
S
vs. I
OUT
35 V
Current with reverse polarity Ground = 35V, V
S
= I
OUT
= 0 4.5 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
BOUNDARY CONDITIONS
Parameter Symbol Conditions Min. Typ. Max. Unit
Sense Resistor R
0
I
OUTFS
= 20mA 172738
Ω
R
0
c = 20mA/I
OUTFS
c ⋅ 17 c ⋅ 27 c ⋅ 38 Ω
Stabilisation Resistor
R
5
I
OUTFS
= 20mA 354045
Ω
R
5
c = 20mA/I
OUTFS
c ⋅ 35 c ⋅ 40 c ⋅ 45 Ω
Load Resistor R
L
Only for 3-wire operation 0 600
Ω
Sum Gain Resistors R
1
+ R
2
20 200
kΩ
Sum Offset Resistors R
3
+ R
4
20 200
kΩ
V
REF
Capacitor C
1
Ceramic 1.9 2.2 5.0
µF
Output Capacitor 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
BCX54/55/56, for example 50 150
DETAILED DESCRIPTION OF FUNCTIONS
AM460 is a modular, universal converter and protector IC which has been specially developed for the condi-
tioning of voltage signals referenced to ground. It has been conceived for both 2- and 3-wire operation
1
in in-
dustrial applications (cf. application on page 8). The functions of AM460 are depicted in the block diagram
(Figure 2) which also illustrates how few external components are required for the operation of this particular
device. Electrical specifications for the external components are given on page 6.
1
The principle of AM460 is such that only the current output can be used in 2-wire operation.