Rev. 1.00
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Rev. 1.00
135
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HT66FM5440
Brushless DC Motor A/D Flash MCU
HT66FM5440
Brushless DC Motor A/D Flash MCU
PSWD
D
Reset
OPA
&
Compare
CKT
AHLHE
Int_AHL_Lim
ISHE
PROTECT
Q
Int_Is
CapTM_Cmp
CapCHE
CAPTM
CapOHE
CapTM_Over
CACPS
=1
CAPOPS
=1
ISPS=0
PSWPS=1
PSWE
PSWPS=0
AHLPS=1
Delay
CKT
AHLPS=0
PROTECTOC
Latch
Reset
OCPSE
Enable
ISPS=1
Protection Function Control
Motor Protection Function Description
The PROTECT mechanism provides three kinds of motor protection features to turn off motor
immediately, allowing action to be taken to protect the motor from damage or to provide additional
safety.
The protection features are:
• Stall detection function
• Over current protection
• Turn off the motor using software
When the motor protection circuit is on, i.e, PROTECT=1, the external Gate Drive transistor pair
can be put into two different protection modes. The first is the Brake Mode where the top arm is off
and the bottom arm is on, and the second is the Free Running Mode where both top and bottom arms
are off. The FMOS bit in the MCF register determines which type is used.
The motor protection circuit can operate in two modes, which is selected by the MPTC2 register.
One mode is the Fault Mode and the other is Pause Mode. In the Fault Mode, activating the protect
function is determined by the trigger source starting status while ending the protect function is
determined by the trigger source disarming status. In the Pause Mode, turning on the protect
function is determined by the trigger source while ending the protection function is determined by
software.
Additionally, the PROTECTOC mechanism is used to immediately switch off the drive signals. If an
over current condition occurs, the drive signals will be switched off directly at the polarity stage and
the preset OCPS protection signals will be output. When the PROTECTOC protection is finished, it
needs to be disabled by software.