TI DRV8870有刷DC马达驱动解决方案

TI公司的DRV8870是有刷DC马达驱动器,两个输入控制H桥驱动器,它包括了4个N-MOSFET,双相控制电流高达3.6A,工作电压6.5-V到45-V,PWM控制接口,具有欠压锁住(UVLO),过流保护(OCP),热关断(TSD)和故障自动恢复等保护功能,主要用在打印机,家用电器,工业设备和其它小型设备.本文介绍了DRV8870主要特性,功能框图,应用框图以及评估板DRV8870EVM特性,电路图和硬件设计文件.

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 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
Integrated Protection Features
VM Undervoltage Lockout (UVLO)
Overcurrent Protection (OCP)
Thermal Shutdown (TSD)
Automatic Fault Recovery

DRV8870应用:

Printers
Appliances
Industrial Equipment
Other Mechatronic Applications

图1.DRV8870功能框图

图2.DRV8870应用框图

评估板DRV8870EVM

DRV8870 H-Bridge PWM Motor Driver Evaluation Module

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.评估板DRV8870EVM外形图

图4.评估板DRV8870EVM电路图(1)

图5.评估板DRV8870EVM电路图(2)

DRV8870EVM设计资料.zip