A3979SLPTR-T

Product Summary

The a3979slptr-t is a complete microstepping motor driver with built-in translator, designed as a pin-compatible replacement for the successful A3977, with enhanced microstepping (1/16 step) precision. It is designed to operate bipolar stepper motors in full-, half-, quarter-, and sixteenth-step modes, with an output drive capacity of up to 35 V and ±2.5 A. The a3979slptr-t includes a fixed off-time current regulator that has the ability to operate in Slow, Fast, or Mixed decay modes. This current-decay control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation. The translator is the key to the easy implementation of the a3979slptr-t. It allows the simple input of one pulse on the STEP pin to drive the motor one microstep, which can be either a full step, half, quarter, or sixteenth, depending on the setting of the MS1 and MS2 logic inputs. There are no phase-sequence tables, high-frequency control lines, or complex interfaces to program. The a3979slptr-t is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened.

Parametrics

a3979slptr-t absolute maximum ratings: (1)Load Supply Voltage VBB: 35 V; (2)Output Current IOUT: ±2.5 A; (3)Logic Supply Voltage VDD: 7.0 V; (4)Logic Input Voltage Range VIN: tW > 30 ns –0.3 to VDD + 0.3 V, tW < 30 ns –1 to VDD + 1 V; (5)Sense Voltage VSENSE: 0.5 V; (6)Operating Ambient Temperature TA Range S: –20 to 85℃; (7)Junction Temperature TJ(max): 150℃; (8)Storage Temperature Tstg: –55 to 150℃.

Features

a3979slptr-t features: (1)±2.5 A, 35 V output rating; (2)Low RDS(On) outputs: 0.28Ω source, 0.22Ω sink, typical; (3)Automatic current decay mode detection/selection; (4)3.0 to 5.5 V logic supply voltage range; (5)Slow, Fast or Mixed current decay modes; (6)Home output; (7)Synchronous rectification for low power dissipation; (8)Internal UVLO and thermal shutdown circuitry; (9)Crossover-current protection.

Diagrams