SSI 32P4904 PRML Read Channel IC With PR4, 8/9 ENDEC, FWR Servo Datasheet

SSI 32P4904 PRML Read Channel with PR4, 8/9 ENDEC, FWR Servo

The SSI 32P4904 is a high performance BiCMOS read channel IC that provides all of the functions needed to implement an entire Partial Response Class 4 (PR4) read channel for zoned recording hard disk drive systems with data rates from 24 to 80 Mbit/s.

Functional blocks include AGC, programmable filter, adaptive transversal filter, Viterbi qualifier, 8,9 GCR ENDEC, data synchronizer, time base generator, and FWR servo. Programmable functions such as data rate, filter cutoff, filter boost, etc. are controlled by writing to the serial port registers so no external component changes are required to change zones. The part requires a single +5V power supply. The SSI 32P4904 utilizes an advanced BiCMOS process technology along with advanced circuit design techniques which result in high performance devices with low power consumption.

FEATURES
• Register programmable data rates from 24 to 80 Mbit/s
• Sampled data read channel with Viterbi qualification
• Programmable filter for PR4 equalization
• 3-tap transversal filter for adaptive PR4 equalization
• 8/9 GCR ENDEC
• Data scrambler/descrambler
• Programmable write precompensation
• Low operating power (0.75W typical at 5V)
• Register programmable power management
• Presettable precoder state
• Register programmable WG polarity
• Dual bit and byte wide bi-directional NRZ data interfaces
• Serial interface port for access to internal program storage registers
• Single power supply (5V ±10%)
• Small footprint 100-Lead TQFP and 100-Lead QFP packages

AUTOMATIC GAIN CONTROL
• Dual mode AGC, analog during acquisition, sampled during read data
• Separate AGC level storage pins for data and servo
• Dual rate attack and decay charge pump for rapid AGC recovery
• Programmable, symmetric, charge pump currents during read data
• Charge pump currents track programmable data rate
• Low drift AGC hold circuitry
• Low-Z input switch
• AGC hold, fast recovery, and AGC input impedance control signals
• Wide bandwidth, precision full-wave rectifier

FILTER/EQUALIZER
• Programmable, 7-pole, continuous time filter provides
• Channel filter and pulse slimming equalization for equalization to PR4
• Programmable cutoff frequency, 3 to 24 MHz
• Programmable boost/equalization, 0 to 12.75 dB
• ±0.6 ns group delay variation from 0.2 ƒc to ƒc, with ƒc = 24 MHz
• Minimizes size and power
• Low-Z input switch
• 3-tap self adapting transversal filter for fine equalization to PR4
• No external components required

Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived SSI 32P4904 PRML Read Channel IC With PR4, 8/9 ENDEC, FWR Servo Datasheet file may be downloaded here without warranties.