ZHCSDA7G July 2014 – February 2018 DRV10983
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 說明 （續）
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3 Feature Description
- 8.4
Device Functional Modes
- 8.4.1 Motor Parameters
- 8.4.2 Starting the Motor Under Different Initial Conditions
- 8.4.3 Motor Start Sequence
- 8.4.4 Start-Up Current Setting
- 8.4.5 Closed Loop
- 8.4.6 Current Limit
- 8.4.7 Lock Detect and Fault Handling
- 8.4.8 AVS Function
- 8.4.9 PWM Output
- 8.4.10 FG Customized Configuration
- 8.4.11
Diagnostics and Visibility
- 8.4.11.1 Motor Status Readback
- 8.4.11.2 Motor Speed Readback
- 8.4.11.3 Motor Electrical Period Readback
- 8.4.11.4 BEMF Constant Readback
- 8.4.11.5 Motor Estimated Position by IPD
- 8.4.11.6 Supply Voltage Readback
- 8.4.11.7 Speed Command Readback
- 8.4.11.8 Speed Command Buffer Readback
- 8.4.11.9 Fault Diagnostics
- 8.5 Register Maps
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機械、封裝和可訂購信息
8.4.4 Start-Up Current Setting
The start-up current setting is to control the peak start-up during open loop. During open loop operation, it is desirable to control the magnitude of drive current applied to the motor. This is helpful in controlling and optimizing the rate of acceleration. The limit takes effect during reverse drive, align, and acceleration.
The start current is set by programming the OpenLCurr[1:0] bits. The current should be selected to allow the motor to reliably accelerate to the handoff threshold. Heavier loads may require a higher current setting, but it should be noted that the rate of acceleration will be limited by the acceleration rate (StAccel[2:0], StAccel2[2:0]). If the motor is started with more current than necessary to reliably reach the handoff threshold, it results in higher power consumption.
The start current is controlled based on the relationship shown in Equation 3 and Figure 20. The duty cycle applied to the motor is derived from the calculated value for ULimit and the magnitude of the supply voltage, VCC, as well as the drive state of the motor.
