TI公司的DRV8872是有刷直流马达(BDC)驱动器,两个逻辑输入控制H桥驱动器,驱动电流高达3.6A,输入采用PWM控制马达速度,工作电压6.5-V到45-V,主要用在打印机,家用电器和工业设备以及其它小型设备.本文介绍了DRV8872主要特性,功能框图,典型应用框图以及评估模块DRV8872EVM主要特性,电路图,材料清单,PCB元件布局图和硬件设计文件.

The DRV8872 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 DRV8872 features integrated current regulation, based on an internal reference voltage 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). Faults are communicated by pulling the nFAULT output low. When the fault condition is removed, the device automatically resumes normal operation.

DRV8872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 R_DS(on) (HS + LS)
3.6-A Peak Current Drive
PWM Control Interface
Integrated Current Regulation
Low-Power Sleep Mode
Fault Status Output Pin
Small Package and Footprint
8-Pin HSOP WithPowerPAD
4.9 × 6.0 mm
Integrated Protection Features
VM Undervoltage Lockout (UVLO)
Overcurrent Protection (OCP)
Thermal Shutdown (TSD)
Fault Reporting (nFAULT)
Automatic Fault Recovery

DRV8872应用:

Printers
Appliances
Industrial Equipment
Other Mechatronic Applications

图1.DRV8872功能框图

图2.DRV8872典型应用框图

评估模块DRV8872EVM

The DRV8872EVM is a complete solution for evaluating the DRV8872 brushed motor driver. It includes avoltage regulator to create 5 V, and a TLC555 timer configured to supply a PWM input to the DRV8872。The EVM also includes a potentiometer to adjust the speed of the motor by varying the duty cycle of thePWM. Jumpers are provided to configure each input to a logic low, logic high, PWM, or to allow usercontrol of the inputs. Test points are provided for ease of monitoring the input and output signals.
The DRV8872EVM only requires connections to the motor and power supply to operate.
The DRV8872 evaluation module (EVM) demonstrates the capabilities and performance of the DRV8872 integrated circuit from Texas Instruments. The EVM includes a 5V regulator and PWM generator. A single power source is required to evaluate the DRV8872.

评估模块DRV8872EVM主要特性:

6.5V to 4.5V Operating Supply Voltage Range
On board 5V regulator
Adjustable PWM duty cycle

图3.评估模块DRV8872EVM外形图

图4.评估模块DRV8872EVM电路图

图5.评估模块DRV8872EVM PCB元件布局图

评估模块DRV8872EVM材料清单见:
评估模块DRV8872EVM材料清单.xls
评估模块DRV8872EVM设计文件见:
评估模块DRV8872EVM设计文件.zip
详情请见:
http://www.ti.com/lit/ds/symlink/drv8872.pdf
和http://www.ti.com/lit/ug/slvuaj5/slvuaj5.pdf
drv8872.pdf
slvuaj5.pdf