5.0 V, 200 M-Bit/Sec PR-IV Hard Disk Drive Read Channel

The Motorola MC34250 is a fully integrated partial response maximum likelihood disk drive read/write channel for use in zoned recording applications. This device integrates the AGC, active filter, 7 tap equalizer, Viterbi detector, frequency synthesizer, servo demodulator, 8/9 rate (0,4/4) Encoder/Decoder with write precompensation and power management in a single 64 pin 10 mm x 10 mm TQFP package.

FEATURES:
• 50 to 200 MBPS Programmable Data Rate
• 800 mW at 200 MBPS and 5.0 V
• Channel Monitor Output
• Programmable AGC Charge Pump Currents with Different Values for Data and Servo Envelope Modes and Gain Gradient Mode
• Programmable AGC Peak Detector Droop Currents with Different Values for Data and Servo Envelope Modes
• Separate AGC Charge Pump Outputs for Data and Servo Modes
• Programmable Dual Threshold Qualifier or Hysteresis Comparator Type Pulse Detector for Servo Data Detection.
• ERD and Polarity Outputs for Servo Timing and Raw Encoded Data
• Integrated 7 pole 0.05° Equiripple Linear Phase Filter with Programmable Bandwidth from 5.0 MHz to 80 MHz and Different Values for Both Data and Servo Modes
• Programmable Symmetrical Boost from 0 to 10 dB and Different Values for Data and Servo Modes
• Programmable Asymmetrical Boost of Up to ±40% of Nominal Filter Group Delay in Both Data and Servo Modes
• 7 Tap Continuous Time Transversal Equalizer with 8 Bit Programmable Tap Weights and Integrated Decision Directed Sign–Sign Least Mean Squared Adaptation
• Internal Offset Cancellation Loops
• Fast Acquisition Data Phase Locked Loop with Zero Phase Restart
• Programmable Data Phase Locked Loop Charge Pump Current
• Integrated Soft Decision Viterbi Detectors with Programmable Merge References
• Integrated 8/9 Rate (0,4/4) Encoder and Decoder with Code Scrambler and Descrambler
• Programmable 2/4/8 Bit NRZ Data Interface
• Programmable Write Precompensation Delays Locked to the Frequency Synthesizer
• Differential PECL Write Data Outputs
• External Write Data Path for DC Erase or Other Non–Encoded Data
• Integrated Write Current DAC
• Programmable Power Management
• Bi–Directional Serial Microprocessor Interface
• Various Test Modes Controlled Via the Serial Microprocessor Interface