TB6556FG_12 Datasheet, PDF (18/22 Pages) Toshiba Semiconductor – 3-Phase Full-Wave Sine-Wave PWM Brushless Motor Controller

TB6556FG
Operating Waveform When Driven by Sine-Wave PWM (CW/CCW = LOW, OS = HIGH,
SS = High)
Generation inside of IC
Modulation signal
Triangular wave (carrier frequency)
Phase U
Phase V
Phase W
Output waveform
U
X
V
Y
W
Z
Inter-line voltage
V_UV
(U-V)
V_VW
(V-W)
V_WU
(W-U)
When driven by a sine wave, the motor is accelerated or decelerated according to the ON duty of TONU as
the amplitude of the modulation symbol changes according to voltage Ve. (See the diagram of the
modulation ratio on page 14.)
Triangular wave frequency = carrier frequency = fOSC/252 (Hz)
Note: At startup, the motor is driven by a sine wave when the Hall signals are 5 Hz or higher (f_OSC = 4 MHz) and the
motor is rotating in the same direction as the TB6556FG controlling it (REV = LOW).
18
2012-10-22