IM483H/IM805H Rev. R032206
40
41
IM483H/IM805H Rev. R032206
S e t t i n g t h e O u t p u t C u r r e n t
The output current can be set on the IM483H/IM805H one of two ways:
1) By connecting the current reference output (P1:1) to the current
adjust input (P1:2) and placing a resistor between this connection and
ground (P2:4). This uses the internal 1mA current source provided at
the current reference pin P1:1 (see figure 7.2).
2) By applying and external reference voltage to P1:2 (see figure 7.3).
Tables 7.1 and 7.2 show both the current adjust resistor values and the refer-
ence voltage required for peak per phase output current settings for the IM483H
and IM805H.
The current adjustment resistor orternal reference voltage used to set the per
phase output current of the IM483H/IM805H sets the peak per phase output of
the sine/cosine waves not the RMS value. Therefore, the peak per phase output
current must be used to determine the value to which the IM483H/IM805H will
be set. See Section 7 “
Determining the Output Current
” for more information.
EXAMPLE: An 8 lead motor in parallel configuration
with a specified unipolar current of 2.0A
2.0A per phase X 2.0 = 4.0 Amps Peak
An 8 lead motor in parallel configuration with
a specified bipolar current of 2.8A
2.8 x 1.4 = 3.92 Amps Peak
Figure 7.2: Current Adjust Resistor Connection
Bottom View
P1
P2
Pin 1
Pin 1
CURRENT REFERENCE
CURRENT ADJUST
SEE TABLES 7.1
AND 7.2 FOR
VOLTAGE VALUES
POWER
GROUND
CURRENT ADJUST
RESISTOR
WARNING! A current adjustment resistor is always necessary to
keep the Driver and/or Motor in a safe operating range.
DO NOT operate the IM483H/IM805H Drivers without a current
adjustment resistor in place.