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HT66FM5440
Brushless DC Motor A/D Flash MCU
HT66FM5440
Brushless DC Motor A/D Flash MCU
BLDC Motor Control Circuit
This section describes how the device can be used to control Brushless DC Motors, otherwise
known as BLDC Motors. Its high level of functional integration and flexibility offer a full range of
driving features for motor driving.
Functional Description
The PWM counter circuit output PWMO has an adjustable PWM Duty to control the output motor
power thus controlling the motor speed. Changing the PWM frequency can be used to enhance the
motor drive efficiency or to reduce noise and resonance generated during physical motor operation.
The internal Mask circuit is used to determine which PWM modulation signals are enabled or
disabled for the motor speed control. The PWM modulation signal can be output using both the
upper arms, GAT/GBT/GCT and the lower arms, GAB/GBB/GCB, of the external Gate Driver
Transistor Pairs under software control.
The Dead-Time insertion circuit is used to ensure the upper and lower Gate Driver Transistor Pairs
are not enabled simultaneously to prevent the occurrence of a virtual power short circuit. The dead
time is selected under software control.
The Staggered circuit can force all the outputs to an off status if the software detects an error
condition which could be due to external factors such as ESD problems or both upper and lower
external Gate Driver Transistor pairs being simultaneously on.
The Polarity circuit can select the output polarity of the BLDC motor output control port to support
many different types of external MOS gate drive device circuit combinations.
The Motor Protect circuit includes many detection circuits for functions such as a motor stall
condition, over current condition, etc.
The Hall Sensor Decoder circuit is a six-step system which can be used control the motor direction.
Twelve registers, each using 6 bits, are used to control the direction of the motor. The motor forward,
backward, brake and free running functions are controlled by the HDCD/HDCR registers. The HA/
HB
/HC or SHA/SHB/SHC can be selected as the Hall Sensor Decoder circuit inputs.
10-bit
PWM counter
CKT
PWMR
f
PWM
PWMO×3
PWMP_Int
PWMD_Int ×3
MPTC1
Mask
Over Current Protection
Stall Protection
S/W Control
PWMB×3
PWMC
DUTR×3
PRDR
HDCD
SHA
SHB
SHC
SA
SB
SC
HDMS
0
1
Hall Sensor
Dcoder
12×6 Register
HDCR
FRS
BRKE
Motor
Protect
CKT
HAT
HAB
HBT
HBB
HCT
HCB
PROTECT
HDCEN
PWM
Complement
BRKE
MPTC2
Hall
Delay
CKT
PTMn-Int
HDLY_MSEL CTM_SEL[1:0]
GAT
GAB
GBT
GBB
GCT
GCB
DTS
PLC
Polarity
Dead
Time
Insert
Staggered
Circuit
AT2
AB2
BT2
BB2
CT2
CB2
AT0
AB0
BT0
BB0
CT0
CB0
AT1
AB1
BT1
BB1
CT1
CB1
MCF
MCD
PWMME
PWMMD
PROTECTOC
Rising/Falling
/Double edge
Detector
CAPTM
Noise
Filter
H1
H3
INTA
INTB
INTC
H2
INTEG0
+
C3EN
-
CMP 3
+
C2EN
-
CMP 2
+
C1EN
-
CMP 1
C3N
C3P
C2N
C2P
C1N
C1P
Hall
Noise
Filter
HA
HB
HC
HSEL
CAPNFT/
CAPNFS/
CAPFIL
HCHK_NUM HNF_MSEL
FHA
FHB
FHC
Note: GAT, GAB, GBT, GBB, GCT, GCB == PWM0H, PWM0L, PWM1H, PWM1L, PWM2H, PWM2L.
BLDC Motor Control Block Diagram