LMD18245T/HALF National Semiconductor, LMD18245T/HALF Datasheet - Page 13

• Manufacturer Part Number: LMD18245T/HALF
• Manufacturer: National Semiconductor

Specifications of LMD18245T/HALF

• Operating Temperature Classification: Automotive
• Package Type: TO-220
• Operating Supply Voltage (min): 12V
• Operating Supply Voltage (max): 55V
• Lead Free Status / RoHS Status: Compliant

The Typical Application
Figure 7 shows the typical application, the power stage of a
chopper drive for bipolar stepper motors. The 20 k
and 2.2 nF capacitor connected between RC and ground set
the off-time at about 48 µs, and the 20 k resistor connected
between CS OUT and ground sets the gain at about 200 mA
ONE-PHASE-ON FULL STEP DRIVE (WAVE DRIVE)
To make the motor take full steps, windings A and B can be
energized in the sequence
where A represents winding A energized with current in one
direction and A* represents winding A energized with current
in the opposite direction. The motor takes one full step each
time one winding is de-energized and the other is energized.
To make the motor step in the opposite direction, the order of
A B A* B* A
FIGURE 7. Typical Application Circuit for Driving Bipolar Stepper Motors
…,
resistor
13
per volt of the threshold for chopping. Digital signals control
the thresholds for chopping, the directions of the winding
currents, and, by extension, the drive type (full step, half
step, etc.). A µprocessor or µcontroller usually provides the
digital control signals.
the above sequence must be reversed. Figure 8 shows the
winding currents and digital control signals for a wave drive
application of the typical application circuit.
TWO-PHASE-ON FULL STEP DRIVE
To make the motor take full steps, windings A and B can also
be energized in the sequence
and because both windings are energized at all times, this
sequence produces more torque than that produced with
AB A*B A*B* AB* AB
…,
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