TMPM4K Motor Control

Microcontroller for

High-Performance PMSM Drive

Systems at Lower Cost

Permanent magnet synchronous motors (PMSMs) have become widely disseminated in the consumer and

industrial fields in recent years. Progress has been made in enhancing the performance of PMSM drive

systems through the introduction of vector control to secure high efficiency while reducing noise. However,

the application of vector control to PMSM drive systems is hindered by issues associated with increased

costs. These costs arise owing to either the necessity for expensive sensors, including current sensors and

position sensors for vector control, or the necessity for advanced technology on the user’s side if a

sensorless control method for PMSM is employed in order to eliminate the requirement for expensive

sensors.

In response to users‘ needs for the easy introduction of vector control into motor drive systems, the Toshiba

Group has been developing and supplying motor control microcontrollers that feature a vector engine (VE)

incorporating certain vector control functions as hardware. We have now commercialized the TMPM4K, a

motor control microcontroller suitable for PMSM drive systems equipped with an improved VE and an

advanced programmable motor driver (A-PMD) to generate inverter control pulse signals. The TMPM4K is

expected to offer high performance due to increased processing speed while reducing costs because of the

smaller number of parts required.

1.Introduction

PMSMs are coming into widespread use for many consumer

and industrial applications because they provide higher

efficiency than induction motors. In particular, in the field of

consumer products, in Japan the enforcement of the Top

Runner System based on the Law on the Rational Use of

Energy (Energy Saving Act) has increased the demand for

energy saving, and highly efficient PMSMs are required.

Although the technique called vector control is effective for

driving PMSMs with high efficiency and low acoustic noise, its

use has been restricted to industrial applications because the

vector control algorithm is complicated.

Under these circumstances, the Toshiba Group has released

the TX03 and TX04 Series of microcontroller units (MCUs) for

consumer motor control applications incorporating a VE,

which implements part of the vector control algorithm as

hardware to simplify the use of vector control

(1)

(Figure 1). Of

the complex mathematical calculations required for vector

control, the vector engine implements, as hardware, the

routine processes that do not vary considerably according to

the application, offloading the central processing unit (CPU)

and thereby increasing overall processing speed. This

hardware implementation also facilitates the use of vector

control for motor control applications (Figure 2).

The Toshiba Group has now developed the TXZ4 Series

(TMPM4K Group) of new motor control MCUs with new

enhancements and higher processing speed than that of the

TX03 and TX04 Series. This article describes the new

enhancements added to the MCUs of the TMPM4K Group as

well as motor control techniques using these enhancements.

Figure 1. Roadmap of Toshiba motor control microcontrollers for consumer applications

From the first-generation TX03 series equipped with VE, we have further improved the processing and

developed the TXZ4 series equipped with new functions.

2.1 High-speed Arm® Cortex®-M4 core and

extensive MCU lineup

Table 1 shows the functional specifications of the MCUs of

the TMPM4K Group, which incorporate the Cortex®-M4 CPU

core from Arm Limited operating at clock frequencies of up

to 160 MHz. The Arm® Cortex®-M4 core contains a

floating-point unit (FPU), providing great convenience for

designers.

CPU performance

TX family

(11 MCUs)

TXZ family

(41MCUs)

Cortex®-M3@80

MHz

Available

Under development

Cortex®-M4@120

MHz

TMPM470

TMPM475

TMPM376FD

TMPM370FY

TMPM372FW

TMPM373FW

TMPM374FW

TX04 series

TXZ4 series

TX03 series

TMPM4K4

TMPM4K2

TMPM4K1

TMPM4K0

TMPM4KQ

TMPM4KP

TMPM4KN

TMPM4KM

TMPM4KL

TMPM375FS TMPM37AFS

On-chip pre-driver

(30 V)

Cortex®-M4@160

MHz

Cortex®-M4@80

MHz

Cortex®-M3@80

MHz

Cortex®-M3@40

MHz

Increased throughput

(New PMD and high-speed ADC

Self-checking function

*This feature includes MCUs under development and is therefore subject to change without notice.

Start of mass production(Year)

Since 2015 2016 2017 2018

2.Features of TMPM4K

Motor Control MCUs

Speed

reference

q-axis current

reference

q-axis

voltage

Phase voltage

(U,V,W)

Communication

pulse signals

Inverter

Estimated

speed

Sensorless

position

controller

d-axis current

q-axis current

3-phase-to-dq

coordinate

transformer

ADC

Software VE MCU hardware

Pase current

(U,V,W)

Current

detection

PMSM

d-axis current

reference

d-axis

voltage

dq-to-3-Phase

coordenate

transformer

Pulse

generator

A-PMD

–

Speed

controller

–

dq*axis

current

controller

Process that need a high

degreeof flexibility are

executed by software

Routine processes are

implemented as hardware

Magnetic

pole positon

*Coordinate system where the d-axis is the magnetic pole direction of motor's

rotor and the q-axis is the direction orthogonal to it.

Figure 2. Configuration of VE

VE implements routine processes for PMSM control as hardware,

reducing the CPU software workload and thereby increaseing overall

prosessing speed.

FPU:

floating -point unit

Ki byte:

kibibyte. 2

bytes

ch:

channel

PWM:

pulse-width modulation

ART: Universal Asynchronous

Receiver Transmitter

TSPI: Twin Serial Peripheral Interface

SPI: Serial Peripheral Interface

SIO: Serial Input / Output

C: Inter-Integrated Circuit

CAN: Controller Area Network

DMA: Direct Memory Access

Part No.

M4K0 M4K1 M4K4 M4KL M4KN M4KQ

Basic

functions

CPU Arm

Cortex

-M4(FPU with FPU)

Max frequency (MHz) 80 160

Data flash memory (Ki bytes)

- 32

Number of I/O ports 22 34 52 51 87 131

Timers

32 (16)- bit timers (ch)

6(12) 5(10) 6(12) 6(12)

Watchdog timer Y Y

32(16)-bit PWM generators (ch)

2(2) 5(6) 6(7) 5(9) 6(11) 6(12)

Analog

circuitry

12-bit ADC (input ch/units) 6/1 10/1 13/1 14/3 22/3 32/3

Op-amps (ch) 1 3 3 3 3

Commu-

nication

units

UART (ch) 2 2 4 3 4 4

TSPI(SPI/SIO) (ch) 1 2 4 2 2 2

C (ch) - 1 1 2 2 2

CAN - - 1 1

Other

peripheral

circuits

Advanced Vector Engine

Plus (A-VE+) (ch)

1 1 1 1

DMAcontroller (ch/units)

32/1 32/1 32/1 32/1

A-PMD

(3-phase complementary PWM generators)

(ch)

1 2 3 3 3

Advanced encoder

input circuits (ch)

1 1 3 3

Supply voltage (V) 2.7 to 5.5 2.7 to 5.5

*This table includes MCUs under development and is therefore subject to change without notice.

Table1. Specifications of TMPM4K microcontroller