TB6588FG

2008-4-25

4

Pin No.

Symbol

I/O

Description

29

FG_OUT

O

Rotation speed output pin (open-drain)

This output is held low at startup and when an abnormality is detected. In sensorless mode,

pulses are generated at 3 ppr according to the back-EMF.

Note:

3 ppr

= 3 pulses per electrical degree (With a four-pole motor, six pulses are generated

per revolution.)

30

FST2

31

FST1

I

Forced commutation frequency select inputs (These pins have a pull-down resistor.)

Forced commutation frequency: cycles per second equivalent to an electrical degree

FST2: FST1

= H:

H:

FST2: FST1

= H:

FST2: FST1

= L or Open: H:

FST2: FST1

32

FPWM

I

H:

33

LA2

34

LA1

I

Lead angle select input (These pins have a pull-up resistor.)

LA2: LA1 ∼

− H or Open : H or Open : 30° lead angleI

LA2: LA1 ∼

− H or Open : L

: 15° lead angle

LA2: LA1 ∼

− L

: H or Open : 7.5° lead angle

LA2: LA1 ∼

− L

: L

: 0° lead angle

35

N.C.

⎯

No connect

36

VM3

⎯

IC.

Fin

Fin

⎯

Fin

This pin provides for thermal dissipation. Board traces should be designed, considering thermal

dissipation from the IC. (Since the fin and the package bottom are electrically connected, the Fin

pin should be connected to insulation or ground.)