[方案]TIDRV8870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,接纳PWM来控制马达速度.器件具有故障和短路掩护特点,包罗UVLO,OCP和TSD掩护.主要用在打印机,家用电器和工业设备等.本文先容了DRV8870主要特点,框架图,应用毗连图,DRV8870评估模块特点,电路图,质料清单和PCB设计原理图.

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主要特点:

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
Small Package and Footprint
8-Pin HSOP WithPowerPAD
4.9 × 6.0 mm

集成掩护特点:

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框架图

图2.DRV8870应用毗连图

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评估模块主要特点:

6.5V to 45V Operating Supply Voltage Range
On board 5V Regulator
Adjustable PWM Duty Cycle
Adjustable Current Regulation

图4.DRV8870评估模块电路图

图5.DRV8870评估模块PCB设计原理图(1)

图6.DRV8870评估模块PCB设计原理图(2)

图7.DRV8870评估模块PCB设计原理图(3)

图8.DRV8870评估模块PCB设计原理图(4)

图9.DRV8870评估模块PCB设计原理图(5)

DRV8870评估模块质料清单见:
DRV8870EVM设计文件.zip

详情请复制打开此衔接地址:
http://www.ti.com/lit/ds/symlink/drv8870.pdf
和http://www.ti.com/lit/ug/slvuaj3/slvuaj3.pdf
drv8870.pdf
slvuaj3.pdf