原标题：TI DRV8870有刷直流马达(BDC)驱动方案

　　TI公司的drv8870是有刷直流马达(BDC)驱动器,具有两个逻辑输入控制由四个N-MOSFET组成的H桥驱动器,电流可高达3.6A,采用PWM来控制马达速度.器件具有故障和短路保护特性,包括UVLO,OCP和TSD保护.主要用在打印机,家用电器和工业设备等.本文介绍了DRV8870主要特性,框图,应用连接图,DRV8870评估模块特性,电路图,材料清单和PCB设计图.

　　The DRV8870 is a brushed-DC motor driver for printers, appliances, industrial equipment, and other small machines. Two logic inputs control the H-bridge driver, which consists of four N-channel MOSFETs that can control motors bidirectionally with up to 3.6-A peak current. The inputs can be pulse-width modulated (PWM) to control motor speed, using a choice of current-decay modes. Setting both inputs low enters a low-power sleep mode.

　　The DRV8870 features integrated current regulation, based on the analog input VREF and the voltage on pin ISEN, which is proportional to motor current through an external sense resistor. The ability to limit current to a known level can significantly reduce the system power requirements and bulk capacitance needed to maintain stable voltage, especially for motor startup and stall conditions.

　　The device is fully protected from faults and short circuits, including under-voltage (UVLO), over-current (OCP), and over-temperature (TSD). When the fault condition is removed, the device automatically resumes normal operation.

　　DRV8870主要特性:

　　H-Bridge Motor Driver

　　Drives One DC Motor, One Winding of a Stepper Motor, or Other Loads

　　Wide 6.5-V to 45-V Operating Voltage

　　565-mΩ Typical RDS(on) (HS + LS)

　　3.6-A Peak Current Drive

　　PWM Control Interface

　　Integrated Current Regulation

　　Low-Power Sleep Mode

　　Small Package and Footprint

　　8-Pin HSOP WithPowerPAD

　　4.9 × 6.0 mm

　　集成保护特性:

　　VM Undervoltage Lockout (UVLO)

　　Overcurrent Protection (OCP)

　　Thermal Shutdown (TSD)

　　Automatic Fault Recovery

　　DRV8870主要应用:

　　Printers

　　Appliances

　　Industrial Equipment

　　Other Mechatronic Applications

　　图1。DRV8870框图

　　图2.DRV8870应用连接图

　　DRV8870评估模块

　　The DRV8870 evaluation module (EVM) demonstrates the capabilities and performance of the DRV8870 integrated circuit from Texas Instruments. The EVM includes a 5V regulator and PWM generator. A single power source is required to evaluate the DRV8870.

　　The DRV8870EVM is a complete solution for evaluating the DRV8870 brushed motor driver. It includes avoltage regulator to create 5 V, and a TLC555 timer configured to supply a PWM input to the DRV8870.

　　The EVM also includes a potentiometer to adjust the speed of the motor by varying the duty cycle of thePWM and a second potentiometer to set the chopping current value. Jumpers are provided to configureeach input to a logic low, logic high, PWM, or to allow user control of the inputs. Test points are providedfor ease of monitoring the input and output signals.

　　The DRV8870EVM only requires connections to the motor and power supply to operate.

　　图3.DRV8870评估模块外形图

　　DRV8870评估模块主要特性:

　　6.5V to 45V Operating Supply Voltage Range

　　On board 5V Regulator

　　Adjustable PWM Duty Cycle

　　Adjustable Current Regulation