Fairchild Semiconductor KA3120
The KA3120 is an ASIC combination chip, which was designed for the HDD, includes the following functions: spindle motor drive, voice coil motor drive, retract and power management. The spindle motor condition is monitored by the FG output and the motor speed control is accomplished via the PWMSP input. The ASIC controls the voice coil motor current via PWMH and PWML inputs and the power management circuit always monitors the power supply voltages.FEATURES
SPINDLE MOTOR DRIVE PART●
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● Soft switching Spindle brake after retract Adjustable brake delay time 2.0A max. current power driver Low output saturation voltage: 1V typical @1.6A PWM decoder & filter for soft switching ORDERING INFORMATION Device KA3120 Package 48-QFPH-1414 Operating Temperature 0 ~ 70°C The digital circuit (ASIC) based start-up, commutation and motor speed control VOICE COIL MOTOR DRIVE PART
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● Trimmed low offset current 1.2A max. current power driver Gain selection and adjustable gain Automatic power down retract function Class AB linear amplifier with no dead zone Low output saturation voltage: 0.8V typical @1.0A Internal full bridge with VPNP (Vertical PNP) & NPN VCM offset monitoring Rev. B MIC-99D001 January 1999 © 1999 Fairchild Semiconductor Corporation 1 PRELIMINARY KA3120 HDD PRODUCTS POWER MONITORING
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● Power on reset with delay Hysteresis on both power comparators Over temperature & over current shut down 5V and 12V powe...