MC556 High Performance Microstepping Driver
MC556 High Performance Microstepping Driver
11
12
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Multiple Drivers
It is recommended to have multiple drivers to share one power supply to reduce cost, if the
supply has enough capacity. To avoid cross interference, DO NOT daisy-chain the power
supply input pins of the drivers. (Instead, please connect them to power supply separately.)
◆
Selecting Supply Voltage
The power MOSFETS inside the MC556 can actually operate 20 ~ +50VDC,
including power input fluctuation and back EMF voltage generated by motor coils during
motor shaft deceleration. Higher supply voltage can increase motor torque at higher
speeds, thus helpful for avoiding losing steps. However, higher voltage may cause bigger
motor vibration at lower speed, and it may also cause over-voltage protection or even
driver damage. Therefore, it is suggested to choose only sufficiently high supply voltage
for intended applications, and it is suggested to use power supplies with theoretical output
voltage of +20 ~ +50VDC, leaving room for power fluctuation and back-EMF.
7. Selecting Microstep Resolution and Output Current
This driver uses an 8-bit DIP switch to set microstep resolution, and motor operating
current, as shown below:
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Microstep Resolution Selection
Microstep resolution is set by SW5, 6, 7, 8 of the DIP switch as shown in the following
table:
Microstep
Steps/rev.(for 1.8
°
motor)
SW5
SW6
SW7
SW8
2
400
OFF
ON
ON
ON
4
800
ON
OFF
ON
ON
8
1600
OFF
OFF
ON
ON
16
3200
ON
ON
OFF
ON
32
6400
OFF
ON
OFF
ON
64
12800
ON
OFF
OFF
ON
128
25600
OFF
OFF
OFF
ON
5
1000
ON
ON
ON
OFF
10
2000
OFF
ON
ON
OFF
20
4000
ON
OFF
ON
OFF
25
5000
OFF
OFF
ON
OFF
40
8000
ON
ON
OFF
OFF
50
10000
OFF
ON
OFF
OFF
100
20000
ON
OFF
OFF
OFF
125
25000
OFF
OFF
OFF
OFF
◆
Current Settings
For a given motor, higher driver current will make the motor to output more torque, but at
the same time causes more heating in the motor and driver. Therefore, output current is
generally set to be such that the motor will not overheat for long time operation. Since
parallel and serial connections of motor coils will significantly change resulting
inductance and resistance, it is therefore important to set driver output current depending
on motor phase current, motor leads and connection methods. Phase current rating
supplied by motor manufacturer is important in selecting driver current, however the
selection also depends on leads and connections.
The first three bits (SW1, 2, 3) of the DIP switch are used to set the dynamic current.
Select a setting closest to your motor’s required current.