原标题：TI DRV8846 3D打印机马达控制器参考设计

　　TI公司的drv8846是高度集成的步进马达驱动器,包括两个H桥和微步进分度器,工作电压4-18V,驱动电流高达1A,主要用在打印机,扫描仪,视频安全摄像机和投映仪.本文介绍了DRV8846主要特性,功能框图,应用电路以及评估板主要特性,电路图和材料清单,以及3D打印机控制器(12V)主要特性,电路图和材料清单.

　　The DRV8846 provides a highly-integrated stepper motor driver for cameras, printers, projectors, and other automated equipment applications. The device has two H-bridges and a microstepping indexer and is intended to drive a bipolar stepper motor. The output block of each H-bridge driver consists of N- channel and P-channel power MOSFETs configured as full H-bridges to drive the motor windings. The DRV8846 is capable of driving up to 1-A full scale

　　output current (with proper heatsinking and TA = 25℃).

　　A simple STEP/DIR interface allows easy interfacing to controller circuits. Pins allow configuration of the motor in full-step up to 1/32-step modes. Decay mode is configurable so that adaptive decay, slow decay, fast decay, and mixed decay can be used. The PWM

　　current chopping off-time can also be selected. A low-power sleep mode is provided which shuts down internal circuitry to achieve very-low quiescent current draw. This sleep mode can be set using a dedicated nSLEEP pin.

　　Internal protection functions are provided for UVLO,overcurrent protection, short circuit protection, and overtemperature. Fault conditions are indicated via a nFAULT pin.

　　DRV8846主要特性:

　　1• PWM Microstepping Motor Driver

　　– Built-In Microstepping Indexer

　　– Up to 1/32 Microstepping

　　– Step/Direction Control

　　• Multiple Decay Modes

　　– Adaptive Decay

　　– Mixed Decay

　　– Slow Decay

　　– Fast Decay

　　• Configurable Off-Time PWM Chopping

　　– 10-, 20-, or 30-μs Off-Time

　　• Adaptive Blanking Time for Smooth Stepping

　　• 4- to 18-V Operating Supply Voltage Range

　　• 1-A Continuous/RMS Output Current (at 25℃)

　　• Low-Current Sleep Mode

　　• 3-Bit Torque DAC to Scale Motor Current

　　• Thermally Enhanced Surface Mount Package

　　• Protection Features

　　– VM Undervoltage Lockout (UVLO)

　　– Overcurrent Protection (OCP)

　　– Thermal Shutdown (TSD)

　　– Fault Condition Indication Pin (nFAULT)

　　DRV8846主要应用:

　　• Printers

　　• Scanners

　　• Video Security Cameras

　　• Projectors

　　图1. DRV8846功能框图

　　图2. DRV8846 PWM马达驱动器电路图

　　图3. DRV8846 典型应用电路图

　　评估板

　　The DRV8846 customer EVM is a platform revolving around the DRV8846, a low voltage dual H-bridge driver and highly configurable power stage. This device has been optimized to drive a single bipolar stepper with up to 32 degrees of internally generated microstepping.

　　The EVM houses an MSP430 microcontroller and a USB interface chip. The USB chip allows for serial communications from a PC computer where a Microsoft® Windows® application is used to schedule serial commands. These commands can be used to control each of the device’s signals, and drive the stepper motor by issuing the step commands at the desired rate.

　　The microcontroller firmware operates using internal index mode.

　　This user’s guide details the operation of the EVM, as well as the hardware configurability of the evaluation module.

　　图4.评估板PCB外形图

　　图5.评估板连接图

　　评估板材料清单:

　　3D打印机控制器(12V)

　　This design is a complete system for controlling 3-axis, single extruder-based 3D printers. The system is managed by the MSP430F5529 LaunchPad and utilizes the DRV8846 for precision stepper motor control. The CSD18534Q5A is used as a low-side switch for the hot bed heater, extruder heater, and cooling fan. The DRV5033 Hall Sensor acts as a contactless limit switch.

　　3D打印机控制器(12V)主要特性:

　　Complete 3D printer controller with MCU, stepper drivers, heater outputs, sensor inputs, and SD card slot.

　　Precise stepper motor current regulation using DRV8846 adaptive decay

　　Hall sensor limit switches are immune to contaminants and never wear out

　　High-current heater outputs from the CSD18534Q5A with low 7.8 mΩ Rds(ON)

　　Powered from a single 12V supply

　　System has been fully tested and proven

　　图.3D打印机TIDA-00405外形图

　　3D打印机TIDA-00405系统材料清单: