36
IM483 Operating Instructions Revision R032306
37
IM483 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!
P
2
P2:2
P2:3
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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-
-
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
