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