Low voltage motor control solution with three-phase BLDC and PMSM designs

The MC9S08AC16 Series devices are members of the low-cost, high-performance HCS08 Family of 8-bit microcontroller units (MCUs). All MCUs in the family use the enhanced HCS08 core and are available with a variety of modules, memory sizes, memory types, and package types. MC9S08AC16 and MC9S08AC8 are used in consumer electronics and industry, and MC9S08AW16A and MC9S08AW8A are used in automotive electronics. This article introduces the main features, block diagram, and main features, detailed circuit diagram, and bill of materials (BOM) of the MC9S08AC16 series.

3-Phase BLDC/PMSM Low- Voltage Motor Control Drive

The MC9S08AC16 Series devices are members of the low-cost, high-performance HCS08 Family of 8-bit microcontroller units (MCUs). All MCUs in the family use the enhanced HCS08 core and are available with a variety of modules, memory sizes, memory types, and package types.

MC9S08AC16 Series Devices

• Consumer & Industrial

— MC9S08AC16

MC9S08AC8

• Automotive

— MC9S08AW16A

— MC9S08AW8A

8-Bit HCS08 Central Processor Unit (CPU)

• 40-MHz HCS08 CPU (central processor unit)

• 20-MHz internal bus frequency

• HC08 instruction set with added BGND instruction

• Background debugging system

• Breakpoint capability to allow single break point setting during in-circuit debugging (plus two more breakpoints in on-chip debug module)

• Debug module containing two comparators and nine trigger modes. Eight deep FIFO for storing change-of-flow addresses and event-only data. Debug module supports both tag and force breakpoints.

• Support for up to 32 interrupt/reset sources

Memory Options

• Up to 16 KB of on-chip in-circuit programmable FLASH memory with block protection and security options

• Up to 1 KB of on-chip RAM

Clock Source Options

• Clock source options include crystal, resonator, external clock, or internally generated clock with precision NVM trimming

System Protection

• Optional computer operating properly (COP) reset with option to run from independent internal clock source or bus clock

• Low-voltage detection with reset or interrupt

• Illegal opcode detection with reset

• Illegal address detection with reset

Power-Saving Modes

• Wait plus two stops

Peripherals

• ADC — 8-channel, 10-bit analog-to-digital convert er with automatic compare function

• SCI — Two serial communications interface modules with optional 13-bit break

• SPI — Serial peripheral interface module

• IIC — Inter-integrated circuit bus module to operate at up to 100 kbps with maximum bus loading; capable of higher baud rates with reduced loading

• Timers — Three 16-bit timer/pulse-width modulator (TPM) modules — Two 2-channel and one 4-channel; each has selectable input capture, output compare, and edge-aligned PWM capability on each channel. Each timer module may be configured for buffered,centered PWM (CPWM) on all channels

• KBI — 7-pin keyboard interrupt module

Input/Output

• Up to 38 general-purpose input/output (I/O) pins

• Software selectable pullups on ports when used as inputs

• Software selectable slew rate control on ports when used as outputs

• Software selectable drive strength on ports when used as outputs

• Master reset pin and power-on reset (POR)

• Internal pullup on RESET, IRQ, and BKGD/MS pins to reduce customer system cost

Package Options

• 48-pin quad flat no-lead package (QFN)

• 44-pin low-profile quad flat package (LQFP)

• 42-pin shrink dual-in-line package (SDIP)

• 32-pin low-profile quad flat package (LQFP)

Figure 1. MC9S08AC16 series block diagram

Figure 2. MC9S08AC16 system clock distribution block diagram

Three-phase BLDC/PMSM low-voltage motor control drive solution

Freescale's 3-Phase BLDC/PMSM Low-Voltage Motor Control Drive is a 3-phase power stage that will operate with DC input voltages in the range 12–24 V, 4 A. Together with the daughter boards, it provides a software-development platform that allows algorithms to be written and tested without designing and building any hardware. It supports a variety of algorithms for PMSM and brushless DC (BLDC) motors.

The 3-Phase BLDC/PMSM Low-Voltage Motor Control Drive contains reverse-polarity protection circuitry, MOSFET-gate-drive circuits, analog -signal conditioning, low-voltage power supplies and bridge MOSFETs. The power devices do not need to be mounted on a heatsink.

There are controller daughter boards available with these controllers:

•MC56F8013/23 — LQFP32

•MC9S08AC16 — LQFP44

•MCF51AC256 — LQFP80

•MC9S08MP16 — LQFP48

•MC56F8006 — LQFP32

Board main features:

•Power supply voltage input 12–24 V DC, extended up to 50 V (see chapter 2.2 Electrical Characteristics for details)

•Output current 4 A

•Power supply reverse polarity protection circuitry

•3-phase bridge inverter (6 MOSFET's)

•3-phase MOSFET gate driver with overcurrent and undervoltage protection

•3-phase and DC-bus-current-sensing shunts

•DC-bus voltage sensing

•3-phase back-EMF voltage-sensing circuitry

•Low-voltage on-board power supplies

•Encoder/hall sensor sensing circuitry

•Motor power and signal connectors

•2 connectors for daughter board connection

•CAN physical layer

•USB interface

•User LED, power-on LED, 6 PWM LED diodes, and SCI activity LED diodes

•Up, down, toggle switches

•Reset push-button


Figure 3. Appearance of three-phase BLDC/PMSM low-voltage motor control driver board

Figure 4. Control drive board block diagram

Figure 5. Phase output circuit diagram

Figure 6. Bus feedback circuit diagram

Figure 7. Control drive board circuit diagram

Figure 8. Control drive board circuit diagram: analog detection-phase current detection

Figure 9. Control drive board circuit diagram: analog detection-post EMF detection

Figure 10. Control and driver board circuit diagram: micro plug and other circuits - encoder/Hall sensor and CANFigure

11. Control and driver board circuit diagram: micro plug and other circuits - switch, user and PWM LEDFigure

12. Control and driver board circuit diagram: micro plug and other circuits - daughter board connector and RESETFigure

13. Control and driver board circuit diagram: micro plug and other circuits - USB/SCI bridge

Figure 14. Control and driver board circuit diagram: MOSFET driver

Figure 15. Control and driver board circuit diagram: power supply circuit

Figure 16. Control and driver board circuit diagram: power supply circuit (2)

Control and driver board bill of materials (BOM):