MC3PHAC Monolithic Intelligent Motor Controller, Rev. 2

10

Freescale Semiconductor

Features

Figure 4. Dynamic Bus Ripple Cancellation

In standalone mode, the base frequency and PWM polarity are specified at the same time during

initialization by connecting either pin 25, 26, 27, or 28 exclusively to the PWMPOL_BASEFREQ input.

During initialization, pins 25, 26, 27, and 28 are cycled one at a time to determine which one has been

connected to the PWMPOL_BASEFREQ input.

Table 3 shows the selected PWM polarity and base frequency as a function of which pin connection is

made. Refer to the standalone mode schematic, Figure 8. Only one of these jumpers (JP1–JP4) can be

connected at any one time.

NOTE

It is not necessary to break this connection once the initialization phase has

been completed. The MC3PHAC will function properly while this

connection is in place.

Table 3. PWM Polarity and Base Frequency Specification in Standalone Mode

Pin Connected to

PWMPOL_BASEFREQ Pin

PWM Polarity

Base Frequency

MUX_IN (JP1)

Logic low = on

50 Hz

SPEED (JP2)

Logic high = on

50 Hz

ACCEL (JP3)

Logic low = on

60 Hz

DC_BUS (JP4)

Logic high = on

60 Hz

PWM1

PWM2

PWM3

PWM4

PWM5

PWM6

MC3PHAC

CORRECTED PWMs

MOTOR PHASE CURRENT WAVEFORMS

UNCOMPENSATED

COMPENSATED

REMOVES 60 Hz HUM