LB1928(1999) Ver la hoja de datos (PDF) - SANYO -> Panasonic

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componentes Descripción

Fabricante

LB1928
(Rev.:1999)

Three-Phase Brushless Motor Driver for Office Automation Equipment

SANYO -> Panasonic 

LB1928

Oscillator frequency (MHz)

3 to 5

5 to 8

8 to 10

C1 (µF)

0.1

0.1

0.1

C2 (pF)

10

None

None

(Reference values)

C3 (pF) R1 (Ω)

47

330k

47

330k

22

330k

The circuit configuration and values are for reference only. The crystal oscillator’s characteristics as well as the

possibility of floating capacitance and noise due to layout factors must be taken into consideration when

designing an actual application.

[Precautions for wiring layout design]

Since the crystal oscillator circuit operates at high frequencies, it is susceptible to the influence of floating

capacitance from the circuit board. Wiring should be kept as short as possible and traces should be kept

narrow.

When designing the external circuitry, pay special attention to the wiring layout between the oscillator and C3

(C2), to minimize the influence of floating capacitance.

[2] External clock input (equivalent to crystal oscillator, several MHz)

When using an external signal source instead of a crystal oscillator, the clock signal should be input from the

XO pin through a resistor of about 5.1 kΩ connected to the pin in series. The XO pin should be left open.

Signal input level

Low : 0 to 0.8V

High : 2.5 to 5.0V

6. Speed lock range

The speed clock range is ±6.25% of the rated speed. When the motor rotation is within the lock range, the LD pin

becomes Low (open collector output). When the motor rotation goes out of the lock range, the ON duty ratio of the

motor drive output is varied according to the amount of deviation to bring the rotation back into the lock range.

7. PWM frequency

The PWM frequency is determined by the capacitance connected to the PWM pin.

f PWM =.. 1/(14400 × C)

The PWM frequency should be between 15 and 25 kHz.

8. Hall input signal

The Hall input requires a signal with an amplitude of at least the hysteresis width (42 mV max.). Taking possible

noise influences into consideration, an amplitude of at least 100 mV is desirable.

9. Forward/reverse switching

Forward/reverse switching of motor rotation is carried out with the F/R pin. If this is performed while the motor is

running, the following points must be observed:

• Feedthrough current during switching is handled by proper circuit design. However, the VCC voltage rise

during switching (caused by momentary return of motor current to power supply) must not exceed the rated

voltage (30V). If problems occur, the capacitance between VCC and GND must be increased.

• If the motor current after switching exceeds the current limiter value, the lower-side transistors go OFF but the

upper-side transistors go into the short brake state, which causes a current flow. The magnitude of the current

is determined by the motor counterelectromotive voltage and the coil resistance. This current may not exceed

the rated current (3.1A). (Forward/reverse switching at high speed therefore is not safe.)

No. 6198-10/11

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