Interfacing The Im483H/Im805H Inputs; Figure 7.5: Current Reduction Interface; Figure 7.6: Input Pull-Up Resistors - Intelligent Motion Systems Excellence in Motion IM805H Operating Instructions Manual

If zero current is required at stand still
then the current reduction output (P1:3)
may be tied directly to the enable input
(P1:11). This will disable the outputs
0.5 seconds after the last step clock
input.
When the current reduction output is
used in this manner an open collector
output or blocking diode is RE-
QUIRED or damage may occur to the
internal circuitry. The diode or open
collector transistor should be placed
after the enable/reduction connection as
shown in figure 7.5.
If a voltage is used to set the output
current the current reduction output
(P1:3) will provide an open drain, ac-
tive low output that occurs 0.5 seconds
after the last step clock input and is
referenced to ground (P2:4) the RDS
matly 6.5Ω.
I n t e r f a c i n g t h e I M 4 8 3 H / I M 8 0 5 H I n p u t s
The inputs to the IM483H/IM805H are internally pulled up to the +5VDC sup-
ply. Figure 7.6 shows the inputs and their associated pull up resistor values. See
Section 2: Hardware Specifications, for resistor tolerance.
When interfacing to the IM483H/IM805H logic inputs an open collector output
is recommended.
IM483H/IM805H Rev. R032206
44
Bottom View
1
FAULT IN
4.99k Ω
MSEL 0
4.99k Ω
MSEL 1
4.99k Ω
MSEL 2
4.99k Ω
MSEL 3
4.99k Ω
SCLK
2.21k Ω
DIR
2.21k Ω
ENABLE
RESET
1.27k Ω
P1

Figure 7.6: Input Pull-Up Resistors

OPEN COLLECTOR INTERFACE
INTERFACE
CIRCUIT
BLOCKING DIODE
INTERFACE
CIRCUIT
Figure 7.5: Interfacing the Current
Reduction Input
of the internal MOSFET is approxi-
ON
P2
+5V
ENABLE/ REDUCTION
INPUT
OR
ENABLE/ REDUCTION
INPUT
SCHOTTKY TYPE