The AMT49700 is a flexible microstepping stepper motor driver that integrates phase current control, built-in converters, and simple motion control. As a single-chip solution, it is designed to operate bipolar stepper motors up to 28 V in full, half, quarter, eighth, and sixteenth step modes.

The AMT49700 reduces microprocessor overhead and is a unique motion profile controller that provides programmable motor acceleration and deceleration, which is especially useful for systems with multiple stepper motors. Additionally, it integrates current sensing, which also reduces the number of external components.

The AMT49700 is ideal for high temperature applications such as headlamp high/low beam and engine management motion control, so it is also suitable for other automotive stepper applications such as HVAC discs and valves.

The current regulator operates at fixed frequency PWM with adaptive hybrid current decay to reduce motor audible noise and improve step size accuracy. The current of each phase of the motor is controlled by a DMOS full-bridge circuit using synchronous rectification technology to improve power dissipation performance. Internal circuitry and timers prevent transconductance and shoot-through when switching between high-side and low-side drivers.

The outputs are short-circuit protected and include low load current detection. Chip-level protection includes over-temperature warning, over-temperature shutdown, over-voltage lockout, and under-voltage lockout.

The AMT49700 is available in a 32-terminal 5 mm x 5 mm QFN package with exposed thermal pad (package type ET).

Features and Benefits

28 V peak motor current up to 1.6 A

Low RDS(on) output, 0.5 Ω sink and pull (typ)

Continuous operation at high ambient temperature

3.7 V to 42 V power supply operation

Adaptive Hybrid Current Decay

Synchronous rectification reduces power dissipation

Output slew control and PWM frequency extension for EMC noise reduction

Internal overvoltage and undervoltage lockout

Thermal Alarm and Over Temperature Shutdown

Short-circuit and open-circuit load diagnostics

Programmable motion control

Configurable via serial interface

Simple step and direction control options

application

Automotive stepper motor

engine management

headlight positioning

HVAC Disc and Valve Control