SLLSFV1 March 2025 MCF8329A-Q1
PRODUCTION DATA
- 1
- 1 Features
- 2 Applications
- 3 Description
- 4 Pin Configuration and Functions
- 5 Specifications
-
6 Detailed Description
- 6.1 Overview
- 6.2 Functional Block Diagram
- 6.3
Feature Description
- 6.3.1 Three Phase BLDC Gate Drivers
- 6.3.2 Gate Drive Architecture
- 6.3.3 AVDD Linear Voltage Regulator
- 6.3.4 Low-Side Current Sense Amplifier
- 6.3.5 Device Interface Modes
- 6.3.6 Motor Control Input Options
- 6.3.7 Bootstrap Capacitor Initial Charging
- 6.3.8 Starting the Motor Under Different Initial Conditions
- 6.3.9 Motor Start Sequence (MSS)
- 6.3.10 Closed Loop Operation
- 6.3.11 Maximum Torque Per Ampere (MTPA) Control
- 6.3.12 Flux Weakening Control
- 6.3.13 Motor Parameters
- 6.3.14 Motor Parameter Extraction Tool (MPET)
- 6.3.15 Anti-Voltage Surge (AVS)
- 6.3.16 Active Braking
- 6.3.17 Output PWM Switching Frequency
- 6.3.18 Dead Time Compensation
- 6.3.19 Voltage Sense Scaling
- 6.3.20 Motor Stop Options
- 6.3.21 FG Configuration
- 6.3.22 DC Bus Current Limit
- 6.3.23
Protections
- 6.3.23.1 PVDD Supply Undervoltage Lockout (PVDD_UV)
- 6.3.23.2 AVDD Power on Reset (AVDD_POR)
- 6.3.23.3 GVDD Undervoltage Lockout (GVDD_UV)
- 6.3.23.4 BST Undervoltage Lockout (BST_UV)
- 6.3.23.5 MOSFET VDS Overcurrent Protection (VDS_OCP)
- 6.3.23.6 VSENSE Overcurrent Protection (SEN_OCP)
- 6.3.23.7 Thermal Shutdown (OTSD)
- 6.3.23.8 Hardware Lock Detection Current Limit (HW_LOCK_ILIMIT)
- 6.3.23.9 Lock Detection Current Limit (LOCK_ILIMIT)
- 6.3.23.10 Motor Lock (MTR_LCK)
- 6.3.23.11 Motor Lock Detection
- 6.3.23.12 MPET Faults
- 6.3.23.13 IPD Faults
- 6.4 Device Functional Modes
- 6.5 External Interface
- 6.6 EEPROM access and I2C interface
- 7 EEPROM (Non-Volatile) Register Map
- 8 RAM (Volatile) Register Map
- 9 Application and Implementation
- 10Device and Documentation Support
- 11Revision History
- 12Mechanical, Packaging, and Orderable Information
6.3.12 Flux Weakening Control
PMSM motors can be operated not only in the constant torque region below the base speed (normally rated speed) but also in the constant power region above the base speed, but the base speed can be varied according to current and voltage limitation. MCF8329A-Q1 provides a flux weakening control, to increase the speed beyond the motor rated speed. The flux weakening can be enabled by setting 1b to FLUX_WEAKENING_EN. The flux weakening control uses a PI control loop as shown in Figure 6-31, to create the Idref. Kp and Ki coefficients for flux weakening loop are configured through FLUX_WEAKENING_KP and FLUX_WEAKENING_KI.
The absolute maximum value of flux weakening current reference (Id_FW) can be limited as a percentage of ILIMIT by configuring FLUX_WEAKENING_CURRENT_RATIO. If FLUX_WEAKENING_CURRENT_RATIO = 0b, then only circular limit is in place, in that case iq2 + id2 is limited to ILIMIT. If Id_FW absolute value increases then iq is reduced to meet circular limit.
User can configure the modulation index reference, Vs_ref (shown in Equation 11) below that the flux weakening is not active and Id_FW is made to zero. The configuration is available in the bits FLUX_WEAKENING_REF ERENCE.
The Idref can be zero or minimum of id reference from flux weakening or MTPA. The variable FLUX_MODE_REFERENCE is available in the volatile memory (RAM) and a non-zero value can overwrite Id_FW and Id_MTPA.
Figure 6-31 Flux Weakening Control