14
CENTENT CN0162 MICROSTEP DRIVE
The CN0162 employs an optocoupler to isolate the STEP PULSE input from the
driver's power supply. The user must provide a +5 VDC supply to operate the
optocoupler circuitry. This permits the use of current sink drivers, such as TTL logic or
open collector transistors, to operate the input. The current requirement is 16 milliamps,
which is compatible with standard TTL outputs. The maximum STEP PULSE rate is
1.5 Mhz. The minimum on or off time is 300 nanoseconds. There are no rise or fall time
limits.
+5 VDC
TERMINAL 10
This is the common anode terminal for the STEP PULSE and DIRECTION optocoupler
LEDs. An ex5 VDC supply is connected to this terminal to provide the source of
LED current for the Step Pulse and Direction inputs. If both are on, 32 mA of current is
required from the +5 VDC supply. The LEDs have antiparallel connected diodes across
them for protection against inadvertent polarity reversal.
If power supply voltages higher than 5 VDC must be used, the STEP PULSE and
DIRECTION inputs require additional series resistance to limit currents to a 16
milliamps level. The following equation determines the value for these resistors:
-180
.016
1.5)
-
(V
=
R
⎟
⎠
⎞
⎜
⎝
⎛
For example, if a +12 volt supply is to be used:
Ω
≈
⎟
⎠
⎞
⎜
⎝
⎛
470
476.25
=
180
-
656.25
=
-180
.016
1.5)
-
(12
=
R
(place a 470 ohm resistors in series with each input)
DO NOT PUT RESISTORS IN SERIES WITH THE +5 VDC TERMINAL.
