SD7540A Stepper Motor Driver

SD7540A Stepper Motor Driver


  • Speeds up to 50 rps (3000 rpm)
  • 400, 1000, 2000, and 5000 steps per turn, programmable
  • 24Vdc - 75Vdc supply voltage
  • Programmable output current up to 4.0 Arms (5.6 A peak)
  • Amplifier disable input
  • Programmable idle current reduction
  • Self-test


SD7540A user manual

SD7540A configuration software










Microstepping Stepper Motor Driver - 4.0 Arms/5.6A peak (75VDC)

The AMCI SD7540A is a powerful stepper motor driver in a low cost, compact package. Externally powered from a 24 – 75VDC power supply, this drive pack can operate up to NEMA size 34 motors.

With up to 4 Arms(5.6 A peak) of half step and microstepping capabilities, this drive pack provides higher speed and torque than any other drive in its class. Yet, it is easy to connect to any differential or transistor pulse and direction motion controller signal.
The SD7540A stepper motor driver can also be easily programmed using AMCI’s SPI interface software and CSMD-5 cable. This Windows-based software allows the programmer quick access to fine-tune the application performance.

Available Versions

SD7540A: 4 Amp rms (5.6 A peak), 24 to 75 Volt driver, Micro-step capable driver for SM23 & SM34 motors, needs external power supply
Price | $285/ea

Note: Pricing is US Domestic only

Consult the factory for availability

Contact Sales


Electrical Specifications

Microstepping Stepper Motor Driver - 4.0 Arms/5.6A peak (75Vdc)
Amplifier Type:Bipolar with two MOSFET H-bridges; average current control, 20 kHz PWM
Number of phases:(2)
Supply voltage:4 Amps max. @ 24Vdc to 75Vdc max.
Inputs:5V differential 15 mA max step, direction, and disable
Motor current:Programmable 0.4-4.0A rms/5.66A peak in 0.4A increments
Steps/revolution:programmable 400, 1000, 2000, 5000
Idle current:Programmable 0-70% of motor current
Programming:RS232 with AMCI SPI interface software
Optional equipment:CSMD-5 serial interface cable

Operational Specifications

Microstepping Stepper Motor Driver - 4.0 Arms/5.6A peak (75VDC)
Current rating:4.0 Arms (average current) / 5.6A peak (peak current)

NOTE: There are 2 ways to express the magnitude of current in microstepping stepper motor drivers, RMS and Peak.

1 amp RMS = 1.414 amp Peak.

AMCI's SD7540A stepper motor drive is rated for 4.0 amp RMS or 5.6 amp Peak.
(See the tutorial on the bottom of this page for more info)
Resolution:400, 1000, 2000, and 5000 steps per revolution
Maximum velocity:motor/load dependent
Motor connections:eight lead series or parallel, six lead series or center tapped, or four lead motors


Motion Controllers

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Distributed I/O

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Stepper Motors

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Contact AMCI Sales today:

telephone: 860-585-1254
email: AMCI sales

Ordering Information

AMCI's sales team takes the hassle out of placing your order. We'll advise on product selection, alternatives, lead times, and present you with point of purchase options. Call (860) 585-1254 or email AMCI sales today!

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