LMD18245T/NOPB National Semiconductor, LMD18245T/NOPB Datasheet - Page 16

• Manufacturer Part Number: LMD18245T/NOPB
• Description: IC H BRIDGE 3A 55V TO-220
• Manufacturer: National Semiconductor

Specifications of LMD18245T/NOPB

• Applications: DC Motor Driver, Stepper Motor Driver, H Bridge
• Number Of Outputs: 1
• Current - Output: 3A
• Voltage - Supply: 12 V ~ 55 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: TO-220-15 (Bent and Staggered Leads)
• Operating Temperature Classification: Automotive
• Package Type: TO-220
• Operating Supply Voltage (min): 12V
• Operating Supply Voltage (max): 55V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Load: -
• Lead Free Status / Rohs Status: Compliant
• Other names: *LMD18245T; *LMD18245T/NOPB; LMD18245T

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The Typical Application
HALF STEP DRIVE WITHOUT TORQUE
COMPENSATION
To make the motor take half steps, windings A and B can be
energized in the sequence
The motor takes one half step each time the number of
energized windings changes. It is important to note that
Top Trace: Phase A Winding Current at 1A/div
Bottom Trace: Phase B Winding Current at 1A/div
Horizontal: 1 ms/div
*500 steps/second
BRAKE A = BRAKE B = 0
FIGURE 11. Winding Currents and Digital Control Signals for Half Step Drive without Torque Compensation
A*B* B* AB* A
A AB B A*B A*
…
(Continued)
16
although half stepping doubles the step resolution, changing
the number of energized windings from two to one de-
creases (one to two increases) torque by about 40%, result-
ing in significant torque ripple and possibly noisy operation.
Figure 11 shows the winding currents and digital control
signals for this half step application of the typical application
circuit.
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