Juno Step Motor Control IC User Guide
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15
15.Application Notes —
MC74113 & MC75113
In This Chapter
General Design Notes
Design Tips
Power Supplies
Clock Generator, Grounding and Decoupling
Reset Signal
Drive-Related Safety and Monitoring Features
PWM High/Low Motor Drive With Leg Current Sensing/Control
Interfacing Juno ICs With A Multi-Axis Magellan IC
15.1 General Design Notes
In the subsequent sections please note that unless otherwise noted MC74113 refers to both the MC74113 and
MC74113N ICs, and MC75113 refers to both the MC75113 and MC75113N ICs.
Logic functions presented in the example schematics are implemented by standard logic gates. In cases where specific
parameters are of significance (propagation delay, voltage levels, etc.) a recommended part number is given.
In the schematics, pins with multiple functions are referenced by the name corresponding to the specified functionality.
For example, pin 56 on the MC74113 is named “PWMHighA/PWMMagA” but will be referenced by the name “PW-
MHighA” in the PWM High/Low motor drive schematic example and “PWMMagA” in the sign/magnitude motor drive
schematic example.
15.1.1 Interfacing to Other Logic Families
When integrating different logic families, consideration should be given to timing, logic level compatibility, and output
drive capabilities. The MC74113 and MC75113 are 3.3V CMOS input/output compatible and cannot be directly
interfaced to 5V CMOS components. In order to drive a 5V CMOS device, level shifters from the 5V CMOS AHCT
(or the slower HCT) families can be used. When using a 5V CMOS component to drive the CP, a voltage divider may
be used or a member from the CMOS 3.3V LVT family may serve as a level shifter.
The schematic designs presented in this chapter are accurate to the best of PMD Corp.’s knowledge. They are
intended for reference only and have not all been tested in hardware implementations.
