Motor Control and I/O Signals
BRAKE: When BRAKE pin is driven 'High', MCT8329A enters brake state. Low-side braking (see Low-Side Braking) is implemented during this brake state.MCT8329A decreases output speed to
value defined by BRAKE_DUTY_THRESHOLD before entering brake state. As long as
BRAKE is driven 'High', MCT8329A stays in brake state. Brake
pin input can be overwritten by configuring BRAKE_INPUT over the
I2C interface.
- DIR: The DIR pin decides the direction of
motor spin; when driven 'High', the sequence is OUTA → OUTC → OUTB, and when driven 'Low'
the sequence is OUTA → OUTB → OUTC. DIR pin input can be
overwritten by configuring DIR_INPUT over the I2C interface.
- DRVOFF: When DRVOFF pin is driven 'High',
MCT8329A turns off all external MOSFETs
by putting the gate drivers into the pull-down state. When DRVOFF is driven
'Low', MCT8329A returns to normal state of
operation, as if restarting the motor. DRVOFF does not cause the device to go to
sleep or standby mode; the digital core is still active. Entry and exit from
sleep or standby condition is controlled by SPEED/WAKE pin.
- SPEED/WAKE: The SPEED/WAKE pin is used to
control motor speed (or power or voltage) and wake up MCT8329A from sleep mode. SPEED/WAKE pin can be configured to accept
PWM, frequency or analog control input signals. The pin is used to enter and
exit from sleep and standby mode (see Table 7-3).
- DACOUT/SOx/SPEED_ANA: The DACOUT/SOx/SPEED_ANA pin
provides a multiplexed functionality and the pin can be configured as a DACOUT
output pin or current sense amplifier output pin or as speed (or power or open
loop voltage) control analog input pin. With the pin DACOUT/SOx/SPEED_ANA
configured as DACOUT, the device allows monitoring of algorithm variables,
speed etc (see GUID-6C88535D-120F-42D1-99B4-D1D0209B1558.html) . With the pin DACOUT/SOx/SPEED_ANA configured as SOx,
the device allows monitoring of integrated current sense amplifier output
(VSOx). With the pin DACOUT/SOx/SPEED_ANA configured as SPEED_ANA
enable the user to give analog control input for speed or power or voltage
through the DACOUT/SOx/SPEED_ANA pin and in that case the SPEED/WAKE pin can be
used as an independent speed or standby control input pin. The pin functionality
can be configured through EEPROM register bit DAC_SOX_ANA_CONFIG.
- EXT_CLK: The EXT_CLK pin can be used to provide an
external clock reference and in that case the internal clock gets calibrated
using the external clock.
- FG: The FG pin provides pulses which are proportional
to motor speed (see GUID-8B220CF6-4794-4C71-81DD-949EE9BD7231.html).
- nFAULT: The nFAULT pin provides fault status in
device or motor operation.