DRV8805 Unipolar Stepper Motor Driver Integrated Circuit 2

Overview

DRV8805 is an integrated 4-channel unipolar stepper motor driver with a stepper/directional interface, capable of controlling low-end driver outputs and allowing for simple control schemes. The four low side driver outputs include four N-channel MOSFETs, with a typical RDS (on) of 500 m Ω. A separate motor power input VM is used as the device power supply and is internally regulated to supply power to the low-voltage side gate driver. By setting the logic high of the nENBL pin, device output can be disabled. The device has several safety functions, including integrated overcurrent protection that limits the motor current to a fixed maximum value, beyond which the device will shut down. Hot shutdown protection enables the device to automatically shut down when the mold temperature exceeds the TTSD limit and restart after the mold reaches a safe temperature. If VM is below the undervoltage lockout threshold, UVLO protection will disable all circuits in the device. Feature description  diode

Output Drive

DRV8805 contains four protected low-end drivers. Each output terminal has an integrated clamp diode connected to a common pin VCLAMP.

VCLAMP can be connected to the main power supply voltage VM. It can also be connected to a Zener or TVS diode to VM, allowing the switching voltage to exceed the main power supply voltage VM. This connection is beneficial when driving loads that require rapid current decay, such as unipolar stepper motors.

In all cases, the output voltage shall not exceed the maximum output voltage specification.

Indexing operation

DRV8805 integrates an indexer that allows motor control through simple stepper and directional interfaces.  diode