BA6477FS

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. FApplications Floppy disk drivers FFeatures 1) 3-phase, full-wave soft switching drive system. 2) Digital servo circuit. 3) Power save circuit. FAbsolute maximum ratings (Ta = 25_C) 4) Hall power supply switch. 5) Motor speed changeable. 6) Index amplifier. FRecommended operating conditions (Ta = 25_C) 532 Motor driver ICs FBlock diagram BA6477FS 533 Motor driver ICs FPin descriptions BA6477FS 534 Motor driver ICs FInput / output circuits (1) Index input (1, 2 pin) BA6477FS (2) FG amplifier (3X5 pin) (3) Speed control (6 pin) (4) External clock input (7 pin) 535 Motor driver ICs (5) Motor output (11X15 pin) (6) Hall bias (16 pin) BA6477FS (7) Hall input (17X22 pin) (8) Integrating amplifier (28, 29 pin) (9) Speed discriminator output (30 pin) (10) Start / stop (31 pin) (11) Index output (32 pin) 536 Motor driver ICs FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 5V) BA6477FS 537 Motor driver ICs FCircuit operation (1) Motor drive circuit The motor driver is based on a 3-phase, full-wave soft switching, current drive system in which the position of rotor is sensed by Hall...