Mechanical and Electromechanical Systems

Microchip PIC Microcontrollers for Motor Control: PIC16F648, PIC16F785 and PIC18F2331

Posted: October 3rd, 2010 | Author: Tom Scarince | Filed under: Electronics, Motor Control | Tags: , , , , | No Comments »

 

While many of the PIC microcontroller models have at least one hardware PWM output channel that could be used to control an h-bridge, we’ll take a quick look at several models that are particularly well suited for servo and stepper motor control applications.  

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National Semiconductor LMD18245 Motor control IC Review

Posted: September 17th, 2010 | Author: Tom Scarince | Filed under: Motor Control, Stepper Motors | Tags: , , | No Comments »

Configuration: Single H-Bridge
Applications: PM DC, Servo, Stepper
Current (continuous): 3 amps
Current (peak): 6 amps
Voltage (max): 60V
Short circuit protection: Yes
Built-in chopper current limitation: Yes, 4-bit linear DAC
Interface: Parallel
Datasheet: LMD18245

Thanks to its voltage and current capability, the LMD18245 is suitable for driving small PMDC servo motors or a medium size stepper motor winding.  It incorporates a unique lossless current sense output.  This chip also includes a 4-bit linear DAC to generate a reference voltage for the internal chopper circuit.  When used in pairs, these chips can run a stepper motor at up to 8 microsteps per full step with reasonable accuracy.   The LMD18200 is a similar IC that lacks the DAC and chopper circuit. 


National Semiconductor LMD18200 Motor control IC Review

Posted: September 16th, 2010 | Author: Tom Scarince | Filed under: Motor Control | Tags: , , | No Comments »

Configuration: Single H-Bridge
Applications: PM DC, Servo, Stepper
Current (continuous): 3 amps
Current (peak): 6 amps
Voltage (max): 60V
Short circuit protection: Yes
Built-in chopper current limitation: No
Interface: Parallel
Datasheet: LMD18200

Thanks to its voltage and current capability, the LMD18200 is suitable for driving small PMDC sevo motors or a medium size stepper motor winding.  It incorporates a unique lossless current sense output that can be used by an external circuit for chopper current control.  The LMD18245 is a very similar part that adds a 4-bit linear DAC and built-in chopper circuit.