New products: DRV8434A and DRV8434S stepper motor driver carriers

Our selection of compact stepper motor driver carriers is expanding with the addition of three new boards based on the DRV8434A and DRV8434S from Texas Instruments. They feature stall detection, adjustable current limiting, over-current and over-temperature protection, and 11 microstep resolutions (down to 1/256-step). They operate from 4.5 V to 48 V and can deliver approximately 1.2 A continuous per phase without a heat sink (up to 2 A peak). The DRV8434A version uses a standard GPIO interface for configuring microstepping and stall detection and a potentiometer for setting the current limit, while the DRV8434S versions use SPI to configure microstepping, stall detection, decay modes, and the effective current limit.

Two DRV8434S carrier versions are available, one with a potentiometer for adjusting the maximum current limit and one with the maximum current limit fixed at 2 A; on both of these, the actual current limit can be scaled down to some percentage of the set maximum through SPI. There are 16 evenly spaced scale settings available, which corresponds to increments of 125 mA on the version with the fixed 2 A maximum. For lower-current applications that would benefit from finer current limit resolution, we recommend the version with the potentiometer. For example, if you set the maximum to 500 mA with the pot, you can then use SPI to scale the current limit down from there in increments of 31 mA.

All carriers are available with and without header pins soldered. The following table compares the key differences among the three versions:

	DRV8434A	DRV8434S (Potentiometer for Max. Current Limit)	DRV8434S (2A Max. Current Limit)
Configuration:	I/O pins	SPI
Control interface:	STEP and DIR pins	STEP and DIR pins or SPI
Stall detection:	through GPIO	through SPI
Current limit:	Potentiometer setting (0–2 A)	Potentiometer setting for max. (0–2 A), scaled with SPI setting (%)	2 A fixed max., scaled with SPI setting (%)
Decay modes available:	1	8
Available versions:	headers included headers soldered	headers included headers soldered	headers included headers soldered

One of the most exciting features of these new chips is their integrated stall detection. We make carriers for a few other stepper motor drivers that provide back EMF outputs, such as the AMIS-30543 and High-Power Stepper Motor Driver 36v4, but processing those signals for stall detection is complex. On the DRV8434A and DRV8434S, the back EMF processing is integrated into the chip and a learning mode is provided to make stall detection simpler and more accessible. Even so, these drivers’ stall detection functionality might not work well in every application, and we have some notes on the product pages with tips on getting it to work (such as using hardware PWM to generate a steady step signal).

Minimal wiring diagram for connecting a microcontroller to a DRV8434A stepper motor driver carrier (1/128-step mode).

Typical wiring diagram for connecting a microcontroller to a DRV8434S stepper motor driver carrier.

The DRV8434A carrier was designed to be as similar to our popular A4988 and DRV8825 stepper motor driver carriers as possible, and it can be used as a drop-in replacement for these in many applications because it shares the same size, pinout, and general control interface. The DRV8434A always operates with a decay mode that TI calls “smart tune ripple control”, which tries to minimize the ripple current through the motor coils for smoother stepping and reduced audible noise in many cases. If additional flexibility is required, the DRV8434S offers a choice of eight decay modes, configurable through SPI; these include slow, mixed, and fast decay as well as the more advanced smart tune dynamic decay and smart tune ripple control modes.

TI also makes a DRV8434 (with no letter A or S at the end) in the same family of drivers. This version doesn’t have the stall detection feature or SPI, but it gives you the same choice of eight decay modes that the DRV8434S does. Why don’t we have a carrier board for the DRV8434 then? Well, we do have the boards, but with the extra long lead times right now, it could still be a while before we have the chips. (These are parts we ordered in June 2021, so more than 16 months ago now!)

DRV8434/DRV8434A Stepper Motor Driver Carrier, bottom view with dimensions.

Our DRV8434A carrier’s printed circuit board is designed to work with the DRV8434 too, and that’s why some of the pins are labeled with two names on the silkscreen. So, for those of you interested in a DRV8434 carrier, those will be coming some day!

Related products

	DRV8434A Stepper Motor Driver Carrier
	DRV8434A Stepper Motor Driver Carrier (Header Pins Soldered)
	DRV8434S SPI Stepper Motor Driver Carrier, Potentiometer for Max. Current Limit
	DRV8434S SPI Stepper Motor Driver Carrier, Potentiometer for Max. Current Limit (Header Pins Soldered)
	DRV8434S SPI Stepper Motor Driver Carrier, 2A Max. Current Limit
	DRV8434S SPI Stepper Motor Driver Carrier, 2A Max. Current Limit (Header Pins Soldered)