DRV8825

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Contents

Description

The DRV8825 is a stepper motor driver board that has on a DRV8825_chip that enables control of stepper motors through arduino type programming firmware and software.
DRV8825 stepper driver module 1a.jpg

The DRV8825 board can supply up to 2.5-A peak or 1.75-A RMS output current (with proper heatsinking at 24 V and 25°C).

A simple step/direction interface allows easy interfacing to controller circuits. Pins allow configuration of the motor in full-step up to 1/32-step modes. Decay mode is programmable. Internal shutdown functions are provided for overcurrent protection, short circuit protection, undervoltage lockout and overtemperature.

It is one of the two most popular add-on stepper motor driver boards, along with the 4988. The increased 1/32 step mode more than makes up for the slight increase in cost compared with the A4988.

Both the the A4988 and DRV8825 boards are interchangeable (note how you put them in), and should work the same on any 3D printer or similar system.
Stepper drivers mixed a4988 drv8825 RAMPS 1a.jpg

Chip Features

  • PWM Microstepping Motor Driver
  • Built-In Microstepping Indexer
  • Five-Bit Winding Current Control Allows
  • Up to 32 Current Levels, 32 step modes, meaning a 360 degree turn can be done in upto 32 steps of 11.25 degrees each.
  • Low MOSFET On-Resistance
  • 2.5-A Maximum Drive Current at 24 V, 25°C
  • Built-In 3.3-V Reference Output
  • 8.2-V to 45-V Operating Supply Voltage Range
  • Thermally Enhanced Surface Mount Package

Comparison table

The following table compares Made in China A4988 Stepper driver boards vs DRV8825 ones, for RepRap use:

A4988 DRV8825
Availability very widely available widely available
Approx. price $6.80 / 5 pieces $10 / 5 pieces
Max. theoretical current 2A 2.5A
Max. microsteps 16 32
PCB color Green / Red Purple
Stepper current adjust. trimpot Yes, near Dir pin Yes, near En pin
Typical Rs value 0.05 Ohm or
0.1 Ohm or
0.2 Ohm
0.1 Ohm
Vref formula (*) I_TripMax= Vref/(8*Rs) I_TripMax= Vref/(5*Rs)
Thermal Overload Protection (**) Yes Yes
PCB layers 2 4
Small heatsink included (***) Almost always Sometimes not
Active cooling required? Recommended Recommended
IC packaging 5x5mm 28-lead QFN 9.7x6.4mm 28HTSSOP

Note that some important technical characteristics from the respective datasheets of the ICs are not directly comparable. For example, the DRV8825 is fully specified in terms of thermal characteristics, the A4988 is not. Another important characteristic that unfortunately is not directly comparable is RDSon, which is specified at different current levels in the respective IC datasheets.

Chip Datasheet

DRV8825 Datasheet, Texas Instruments

External notes/references

See also

DRV8825_chip

A4988 vs DRV8825 Chinese Stepper Driver Boards

Motor_Shield_Standard