ROHM BA6477FS Datasheet

Motor driver ICs

FDD spindle motor driver

BA6477FS

The BA6477FS is a one-chip IC designed for driving FDD spindle motors. This high-performance IC employs a 3-phase,
full-wave soft switching drive system, and contains a digital servo, an index amplifier, and a power save circuit. The com­pactly packaged IC reduces the number of external components required.

Applications
Floppy disk drivers

Features

1) 3-phase, full-wave soft switching drive system.

2) Digital servo circuit.

3) Power save circuit.

Absolute maximum ratings (Ta = 25C)

4) Hall power supply switch.

5) Motor speed changeable.

6) Index amplifier.

Recommended operating conditions (Ta = 25C)

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Motor driver ICs BA6477FS

Block diagram

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Motor driver ICs BA6477FS

Pin descriptions

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Motor driver ICs BA6477FS

Input/output circuits

(1) Index input (1, 2 pin)

(2) FG amplifier (35 pin)

(3) Speed control (6 pin) (4) External clock input (7 pin)

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