MC3PHAC Monolithic Intelligent Motor Controller, Rev. 2

30

Freescale Semiconductor

Operation

•

PWMPump — This state is entered from the PWM0RPM state when a CmdFwd or CmdRev

command is received. In this state the top PWM outputs are driven off while the bottom PWM

outputs are driven with a 50 percent duty cycle. This allows high side transistor gate drive circuits

which require charge pumping from the lower transistors to be charged up prior to applying full

PWMs to energize the motor. This state is automatically exited after the defined amount of time

•

FwdAccel — This state is entered from the PWMPump state after a CmdFwd command is

received and the timeout interval from the PWMPump state is completed. This state can also be

entered from the FwdSteady state if the Speed In variable is increased above the actual current

speed and the RevDecel state if the actual motor speed equals 0 r.p.m. when a CmdFwd command

has been received. In this state the motor is accelerated forward according to the chosen

parameters.

•

FwdSteady — This state is entered from the FwdAccel state after the actual motor speed has

reached the requested speed defined by the Speed In variable. In this state, the motor is held at a

constant forward speed.

•

FwdDecel — This state is entered from the FwdAccel or FwdSteady states whenever a CmdStop

or CmdRev command is received. This state can also be entered from the FwdSteady state if the

Speed In variable is decreased below the actual current speed. In this state, the motor is

decelerated forward according to the chosen parameters.

•

RevAccel — This state is entered from the PWMPump state. After a CmdRev command is

received and the timeout interval from the PWMPump state is completed. This state can also be

entered from the RevSteady state if the Speed In variable is increased above the actual current

speed and the FwdDecel state if the actual motor speed equals 0 r.p.m. when a CmdRev command

has been received. In this state, the motor is accelerated in reverse according to the chosen

parameters.

•

RevSteady — This state is entered from the RevAccel state after the actual motor speed has

reached the requested speed defined by the Speed In variable. In this state, the motor is held at a

constant reverse speed.

•

RevDecel — This state is entered from the RevAccel or RevSteady states whenever a CmdStop

or CmdFwd command is received. This state can also be entered from the RevSteady state if the

Speed In variable is decreased below the actual current speed. In this state, the motor is

decelerated in reverse according to the chosen parameters.

•

SetBaseFreq — This state is entered from any state whenever a CmdBaseFreqxx command is

received. In this state, the motor frequency at which full voltage is applied is configured and the

state is then automatically exited and the original state is re-entered.

•

SetAccel — This state is entered from any state whenever a write to the Acceleration variable

occurs. In this state, the motor acceleration is configured and the state is then automatically exited

and the original state is re-entered.

•

SetSpeed — This state is entered from any state whenever a write to the Speed In variable occurs.

In this state, the requested motor speed is configured and the state is then automatically exited and

the original state is re-entered.

•

entered from the PWMHighZ state, in which case, the PWM outputs remain in the High Z state).

When the problem causing the fault condition is removed, a timer is started which will wait a

specified amount of time (which is user programmable) before exiting this state. Under normal