IMS IM483 - Figure 7.2 Current Adjust Resistor Placement; Table 7.1 Current Adjust Resistor Values

36 IM483 Operating Instructions Revision R032306
37IM483 Operating Instructions Revision R032306
S e t t i n g t h e O u t p u t C u r r e n t
The IM483 uses an internal 1 milliamp current source to establish the
reference voltage needed to control the output current. This voltage is
programmed by means of an external 1/8 watt or higher, 1 percent resis-
tor connected between P2:2 (Current Adjust) and P2:3 (Power Ground).
The relationship between the output current and the current adjust resis-
tor value is expressed as follows:
Output Current = .002 X Resistor Value (Ω)
Figure 7.2 illustrates the connection of this resistor. Table 7.1 lists the
resistor values for the driver output current in 200 milliamp increments.
NOTE: Resistor leads should
be
as short as possible to
minimize the amount of noise
coupled into the driver!
P2
P2:2P2:3
Driver Output Current =
.002 X Resistor
Value ( )
Current Adjust Resistor
1/8 W 1
%
Figure 7.2: Current Adjust Resistor Placement
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4.0 002 4.2 0121
6.0
103
6.2
0031
8.0 293 8.2 0041
0.1
994
0.3
0051
2.1 095 2.3 0851
4.1
896
4.3
0961
6.1 787 6.3 0871
8.1
788
8.3
0191
0.2 0001 0.4 0002
2.2
0011
-
-
Table 7.1: Current Adjust Resistor Values
WARNING! Do not operate the IM483 Driver without a Current
Adjustment Resistor!
A resistor MUST be placed between the Current Adjust Input (Pin 2
on P2) and ground (Pin 3 on P2) to keep the IM483 Driver and/or