Advertisement
10. Lock protection
It monitors the motor rotation by the hall signal and operates when the zero cross of the hall signal can not be
detected for certain time (T
for 1ms(typ) and then all output power transistors are turned off. The motor drive resumes certain time (T
after the lock protection operates.
T
= 0.4s (typ)
ON
T
= 4s (typ)
OFF
HP-HM
FG
OUT1
OUT2
RDO
FG is outputted by the hall signal even while the lock protection is operating.
In case the zero cross of the hall signal is detected twice in re-startup, the lock protection is cleared and the
RDO signal outputs low again.
11. Quick Start
During T
of lock protection, lock protection is cleared when the voltage of VSP pin is set to V
OFF
When V
or more is applied to the VSP pin again, the motor restarts operating quickly without waiting for
AD(L)
the end of the T
OFF
HP-HM
FG
OUT1
OUT2
RDO
VSP
Because the voltage of VSP pin is detected through A/D circuit, the voltage of VSP pin should be kept at V
or less for VSP response time (T
Quick start is disabled when the minimum of the duty is configured by applying the voltage of V
to VMI pin.
) or more. When lock protection operates, the upper output transistor is turned off
ON
1ms
20us
OFF (Hi-Z)
L
OFF (Hi-Z)
T
T
ON
OFF
term.
1ms
20us
OFF (Hi-Z)
L
T
ON
) or more in order to clear the lock protection.
VSP
1ms
20us
L
OFF (Hi-Z)
OFF (Hi-Z)
T
ON
OFF (Hi-Z)
T
OFF
21
TC78B002FNG
)
OFF
or less.
AD(L)
0.5V
0.55V
AD(L)
or more
AD(L)
2013-10-17
Advertisement
