Datasheet

Industrial Converter and Protector IC AM460
analog microelectronics
April 2003
10/18
• When using current output pin IOUT (in conjunction with the external transistor) the value of V
S
is depend-
ent on that of the relevant load resistor R
L
(max. 600Ω) used by the application. The minimum system sup-
ply voltage V
S
is then:
minmax CCLOUTS
VRIV
+≥
(10)
Here, I
OUTmax
stands for the maximum output current and V
CCmin
for the minimum IC supply voltage which is
dependent on the selected reference voltage:
V1
min
+≥
REFCC
VV
(11)
The working range resulting from Equation 10 is described in Figure 4. Example calculations and typical values
for the external components can be found in the example applications from page 12 onwards.
Connecting OP2 as a current source
The additional operational amplifier OP2 can easily be connected up as a constant current source. Using the cir-
V
S
[V]
R
L
[
Ω
]
6
35
V
CCmin
= 6V
R
Lmax
= 600
Ω
I
OUTmax
= 20mA
18
R
VV
I
L
SCCmin
OUTmax
≤
−
2412
600
Operating range
0
300
0
Figure 4: Working range in conjunction with the load resistor
V
BG
AM460
OP2
1
R
SET
OP2 connected as current source
2
I
S
Figure 5: Connecting up a constant current source