The A5984 is a complete microstepping motor driver with
built-in translator for easy operation. It is designed to operate
bipolar stepper motors from full-step up to 1/32 step modes.
Step modes are selectable by MSx logic inputs. It has an output
drive capacity of up to 40 V and ±2 A.
A5984 introduces a proprietary QuietStepTM algorithm to optimize the current waveform over a
wide range of stepper speeds and stepper motor characteristics. QuietStepTM adjusts on-the-fly the amount of fast decay during a
PWM cycle to keep current ripple at a low level over the
various operating conditions. This adaptive feature improves
performance of the system resulting in reduced audible motor
noise, reduced vibration, and increased step accuracy.
The translator is the key to the easy implementation of the
A5984. Simply inputting one pulse on the STEP input drives
the motor one microstep. There are no phase sequence tables,
high frequency control lines, or complex interfaces to program.
The A5984 interface is an ideal fit for applications where a
complex microprocessor is unavailable or is overburdened.
The ET package meets customer requirements for no smoke
no fire (NSNF) designs by adding no-connect pins between
critical output, sense, and supply pins. So, in the case of a
pin-to-adjacent-pin short, the device does not cause smoke
or fire. Additionally, the device does not cause smoke or fire
when any pin is shorted to ground or left open.
Internal synchronous rectification control circuitry is provided to
improve power dissipation during PWM operation. Internal circuit
protection includes: thermal shutdown with hysteresis, undervoltage
lockout (UVLO), and crossover-current protection. Special power-on
sequencing is not required.
The A5984 is supplied in three surface mount packages: two QFN
packages, the 4 mm × 4 mm, 0.75 mm nominal overall height ES
package, and the 5vmm × 5 mm × 0.90 mm ET package. The LP
package is a 24‑pin TSSOP. All three packages have exposed pads
for enhanced thermal dissipation, and are lead (Pb) free (suffix –T),
with 100% matte-tin-plated leadframes.
