OM5198K

GENERAL DESCRIPTION

Overview
The OM5193H is a combination of a voice coil motor and a spindle motor driver with embedded servo controller designed for use in disk drives. Configuration and control registers are set via a 3-wire serial port running up to 30 MHz to interface commonly to a microcontroller or a digital signal processor.
The device operates at 5 and 12 V power supplies and integrates safety functions such as power stages overvoltage protection, power and temperature monitor, over-temperature shutdown and dynamic brake-after-park.
The device is contained in a QFP80 package with 18 pins connected to the leadframe thus providing low thermal resistance.

FEATURES

Servo control
• 10-bit VCM Digital-to-Analog Converter (DAC)
• 7-channel 10-bit Analog-to-Digital Converter (ADC)
• Programmable spindle commutation control logic
• 3-wire serial interface
• Two stand-alone operational amplifiers (op-amps) with outputs connected to the ADC
• Analog multiplexer with two inputs used to select VCM seek mode or track- following mode.

Motor control

SPINDLE MOTOR DRIVER
• 3-phase output motor driver
• 1.9 A maximum available start-up current
• Total Rds(on) = 0.6 Ω (typical) at 25 °C
• Back ElectroMotive Force (BEMF) processing for sensorless motor commutation
• Linear current control
• External current sense resistor
• External current control loop compensation
• Adjustable slew rate control
• Short-circuit brake
• Adjustable brake-after-park delay time.

VOICE COIL MOTOR DRIVER

• 1.5 A maximum current capability
• Total Rds(on) = 0.8 Ω (typical) at 25 °C
• Linear class AB output with low cross-over distortion delay
• Precision current control loop with external current sense resistor
• Programmable seek and track-following mode with adjustable current loop gain
• External current control loop compensation
• Precharge during brake mode
• 20 kHz current control loop bandwidth
• Parking function
• Adjustable park voltage with limiter.

Miscellaneous items

• Precision low voltage 5 and 12 V power monitor with hysteresis
• Precision internal voltage reference for servo and power control circuits
• Thermal sense circuit with over-temperature shutdown sensor
• Internal charge pump voltage generator
• Automatic brake-after-park at power-down, thermal shutdown or sleep mode
• Sleep mode: low power consumption mode.

APPLICATIONS

• 12 V hard disk drive products.