BA6664FM Ver la hoja de datos (PDF) - ROHM Semiconductor

Número de pieza

componentes Descripción

fabricante

BA6664FM

1ch Spindle Motor Driver ICs

ROHM Semiconductor 

BA6859AFP-Y,BA6664FM,BD6671FM

Technical Note

●Reverse Rotation Detection Function

H2+ +

H2-

-

H3+ +

H3-

-

D-FF

DQ

CK

EC

ECR

+

-

Fig.13

H:OUTPUT.OPEN

(HIGH-IMPEDANCE)

Actual motor rotation at reverse detection

EC < ECR: Forward torque (forward rotation)

EC > ECR: Deceleration (forward rotation)

When the motor rotates in the reverse direction, the reverse rotation

detection function will operate and the output will be in an open state.

The motor rotates in a reverse direction with inertial force.

Fig. 13 shows the construction of the reverse rotation detection circuit.

・Forward rotation (EC<ECR)

Stop

Fig. 9 shows the phase relation of the H2+ and H3+ Hall input signals,

in which case the reverse rotation detection circuit will not work.

・Reverse rotation (EC>ECR)

The phase relation of the H2+ and H3+ signals are opposite to that when the motor is rotating in the forward direction.

Therefore, the reverse rotation detection circuit operates, and the output is turned off and open.

●FR Signal Output (BA6859AFP-Y, BA6664FM)

FR output signal pin outputs the FR signal of low(L) or high(H) after detecting the motor rotation direction.

Motor rotation direction

FR signal output

Forward

“H”

Reverse

“L”

●Brake Mode Change (BA6664FM, BD6671FM)

By applying high-level voltage to the BR pin, the brake mode for the following condition can be changed: EC > ECR.

EC<ECR

EC>ECR

L

BR

H

Forward rotation

Forward rotation

Reverse rotation brake

Short brake

When the BR pin is set to high level and used in short-brake mode, open the SB pin.

The BR pin has a temperature characteristics of approximately -5 mV/℃. Use the BR pin within the permissible input range.

●Short Brake (BA6859AFP-Y, BA6664FM)

OFF

OFF

OFF

ON A ON A ON A

O

When the short-brake pin is set to high level, as shown in Fig.18, the output

transistor (3-phase) on the high side will be turned off and the output transistor

(3-phase) on the low side will be turned on. The short brake pin has a

temperature characteristic of approximately -5 mV/℃. Keep the input voltage

range (see Fig12) in mind.

MOTOR

Fig.14

●Hall Input

The Hall element allows both serial and parallel connections.

VCC

H3

H2

H1

VCC

H1

H2

H3

Set the Hall input voltage between 1.0 and 4.0 V. Compute the

resistance between the VH and VCC pins in consideration of the

flowing current of the Hall device.

15-pin (Hall Bias)

Parallel Connection

15-pin (Hall Bias)

Serial Connection

Fig.15

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© 2010 ROHM Co., Ltd. All rights reserved.

14/17

2010.06 - Rev.A

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