TB6556F TOSHIBA [Toshiba Semiconductor], TB6556F Datasheet - Page 11

• Manufacturer Part Number: TB6556F
• Description: 3-Phase Full-Wave Sine-Wave PWM Brushless Motor Controller
• Manufacturer: TOSHIBA [Toshiba Semiconductor]

Functional Description
1. Basic operation
2. Select drive function
3. V
4. Dead time function: upper/lower transistor output off-time
signal reaches number of rotations f = 5 Hz or higher, the rotor position is estimated according to the
positional signal and a modulation wave is generated. The modulation wave and the triangular wave are
compared; then the sine-wave PWM signal is generated and the motor is driven.
(1)
(2)
(3)
short circuit caused by the simultaneous turning on of upper and lower external power devices. When a
square wave is generated in full-duty cycle mode, the dead time function is turned on to prevent a short
circuit.
T
f
osc
OFF
e
The motor is driven by the square-wave turn-on signal based on a positional signal. When the positional
This function can select drive mode.
When the motor is driven by sine-wave PWM, dead time is digitally generated in the IC to prevent a
HIGH or OPEN
voltage command signal function and function to stabilize bootstrap voltage
= reference clock (crystal oscillation)
From start to 5 Hz: When driven by square wave (120° turn-on) f = f
5 Hz~: When driven by sine-wave PWM (180° turn-on); when f
SS pin
HIGH or OPEN = Sine-wave PWM drive (180° turn-on mode)
LOW = Square-wave drive (120° turn-on mode)
values above are obtained when fosc = 4.19 MHz.
Note: If the position sensing signal is f = 5 Hz or lower, the driver is 120° turn-on mode even when SS =
When the voltage command signal is input at V
When the voltage command signal is input at 1.0 V < Ve < = 2.1 V:
When the voltage command signal is input at Ve > 2.1 V:
transistor at regular (carrier) cycle. (ON duty is approx. 8%)
Note: At startup, turn the lower transistor on for a fixed time with 1.0 V < Ve < = 2.1 V to charge the upper
Td Pin
Turns off output (gate protection)
Turns on the lower transistor at the regular (carrier) cycle. (ON duty is approx. 8%.)
During sin-wave drive, outputs drive signal as it is. During square-drive, forcibly turns on the lower
LOW
HIGH.
transistor gate power supply.
100%
PWM Duty
Internal Counter
(1)
16/f
8/f
1.0 V
osc
osc
(2)
2.1 V
(3)
5.4 V
1.9 µs
3.8 µs
11
T
OFF
e
< = 1.0 V:
V e
osc
= 4 MHz, approx. 5 Hz
osc
/(2
12
× 32 × 6)
TB6556F/FG
2005-01-19