ZHCSFZ1A January 2017 – July 2018 DRV8886
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
- 1 特性
- 2 應(yīng)用
- 3 說(shuō)明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 Stepper Motor Driver Current Ratings
- 7.3.2 PWM Motor Drivers
- 7.3.3 Microstepping Indexer
- 7.3.4 Current Regulation
- 7.3.5 Controlling RREF With an MCU DAC
- 7.3.6 Decay Modes
- 7.3.7 Blanking Time
- 7.3.8 Charge Pump
- 7.3.9 Linear Voltage Regulators
- 7.3.10 Logic and Multi-Level Pin Diagrams
- 7.3.11 Protection Circuits
- 7.4 Device Functional Modes
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文檔支持
- 12機(jī)械、封裝和可訂購(gòu)信息
封裝選項(xiàng)
機(jī)械數(shù)據(jù) (封裝 | 引腳)
散熱焊盤(pán)機(jī)械數(shù)據(jù) (封裝 | 引腳)
訂購(gòu)信息
8.2.2.1 Stepper Motor Speed
The first step in configuring the DRV8886 device requires the desired motor speed and microstepping level. If the target application requires a constant speed, then a square wave with frequency ƒstep must be applied to the STEP pin.
If the target motor speed is too high, the motor does not spin. Make sure that the motor can support the target speed.
Use Equation 3 to calculate ƒstep for a desired motor speed (v), microstepping level (nm), and motor full step angle (θstep).
The value of θstep can be found in the stepper motor data sheet, or written on the motor.
For the DRV8886 device, the microstepping level is set by the Mx pins and can be any of the settings listed in Table 11. Higher microstepping results in smoother motor motion and less audible noise, but increases switching losses and requires a higher ƒstep to achieve the same motor speed.
Table 11. Microstepping Indexer Settings
| M1 | M0 | STEP MODE |
|---|---|---|
| 0 | 0 | Full step (2-phase excitation) with 71% current |
| 0 | 1 | 1/16 step |
| 1 | 0 | 1/2 step |
| 1 | 1 | 1/4 step |
| 0 | Z | 1/8 step |
| 1 | Z | Non-circular 1/2 step |
For example, the motor is 1.8°/step for a target of 120 rpm at 1/8 microstep mode.
