TB6575FNG Toshiba, TB6575FNG Datasheet - Page 5

• Manufacturer Part Number: TB6575FNG
• Manufacturer: Toshiba

Specifications of TB6575FNG

• Function: Controller
• Vopmax (vm*): 5.0V (5.5V)
• Io (lpeak): 20mA
• Sinusoidal Current Wave: no
• Sensor-less: yes
• Speed Feedback Loop: no
• Package: SSOP24
• Rohs Compatible†: yes

Functional Description
1. Sensorless drive
2. Startup operation
START_SP (8 pin)
mode, and then the rotation is started in forced commutation mode by applying a PWM signal to the motor.
As the rotor moves, back-EMF is acquired.
position signal input pin, automatic switching occurs from the forced commutation PWM signal to the
natural commutation PWM signal (which is generated based on the back-EMF sensing) to drive a BLDC
motor in sensorless mode.
the rotor is aligned to a known position in DC excitation mode and then the rotation is started in forced
commutation mode. An external capacitor sets the times that the TB6575FNG stays in DC excitation and
forced commutation modes. Those times vary depending on the motor type and motor loading. Thus, they
must be adjusted experimentally.
voltage decreases to half V
switching occurs to forced commutation mode represented by (b). The duty cycles for DC excitation and
forced commutation modes are determined according to the SC pin voltage. When the rotation frequency of
the motor exceeds the forced commutation frequency, the motor switches to sensorless mode. The duty
cycle for sensorless mode is determined by the SC pin voltage.
On receiving an analog voltage command input, the rotor is aligned to a known position in DC excitation
When a signal indicating the polarity of each of the phase voltages including back-EMF is applied to the
When the motor is stationary, there is no back-EMF and the motor position is unknown. For this reason,
The rotor is aligned to a known position in DC excitation mode for period (a), during which the IP pin
(a): DC excitation period: T
(b): Forced commutation period
V
SC (2 pin)
SP
IP (9 pin)
(5 pin)
DD
T
FIX
(a) (b)
level. The time constant for the period is determined by C
FIX
(typ.) = 0.69 × C2 × R1 (s)
V
T
UP
AD (L)
V
V
DD
DD
2
5
T
UP
V
V
GND
(typ.) = C1 × V
SP
SP
≥ 1.0 (V)
V
C
SP
1
SP
5
2
/3.8 µA (s)
C
2
2
TB6575FNG
TB6575FNG
9
and R
R
1
2008-9-11
1
. After that,
8