TZA1000T

GENERAL DESCRIPTION

The TZA1000 is a single-chip read-write amplifier for single-channel QIC (Quarter Inch Cartridge) systems with MR heads. It can be used with both SIG (Sensor in Gap)- and yoke-type MR heads and is designed to be used in conjunction with the Philips SZA1000 digital equalizer IC (although it can also function as a stand alone unit). This combination is flexible enough to be used with all popular tape backup formats including QIC 80, QIC 3010, QIC 3020, QIC 3080, QIC 5010, Travan 1, Travan 2, Travan 3 and Travan 4 and to be forward compatible with their single channel successors.

FEATURES

• 3-wire serial interface for programming
• On-chip Digital-to-Analog Converters (DAC) for:
– MR (Magneto Resistive) sense bias current
– MR DC bias current
– Write current
• Low noise differential input stage: typically 0.65 nV/√Hz (Zi = 0 Ω)
• Magnetic feedback circuit to handle large output signals
• MR DC bias current circuit
• Very fast write current rise and fall times with near rail-to-rail voltage swing
• Maximum write current of 100 mA: ready for high coercivity tape
• Low noise read amplifier for reading track height servo signals with the write coil
• Very few external components required
• On board registers for easy format or bit rate selection
• Fast read-after-write recovery time
• Test circuit for yoke-type heads
• Switchable differentiator for yoke-type heads, with programmable cut-off frequencies
• Anti-aliasing low-pass filter, with programmable cut-off frequencies
• AGC (Automatic Gain Control) options: internally (digitally) controlled, externally controlled or fixed gain
• Hold input for fast AGC freeze
• Input for fast reader/writer (track height servo) signal selection
• Power fail detection on both 5 and 12 V lines (status can be read from the read register)
• Write unsafe detection
• Provides an accurate reference voltage (for AD conversion)
• Very simple interconnection with the SZA1000 QIC digital equalizer
• +5 V ±10% and +12 V ±10% supply voltages
• Low power standby, active and test modes.