VM7200

The VM7200 is a high-performance, very low-power read! write preamplifier designed for use with external thin-film or MIG recording heads. This circuit will operate on a single 5-volt power supply and is ideally suited for use in battery powered disk drives. The VM7200 provides write current and data protection circuitry, and low noise read functions for up to eight read/write heads. When deactivated, the device enters a sleep made which reduces power dissipation to 7.5 mW. Data protection circuitry is provided to ensure that the write current source is totally disabled during power supply power up/power down conditions. Write-to-read recovery time is minimized by elimi- nating common mode output voltage swings when switching between modes. The VM7200 is available in several different packages. Please consult VTC for package availability.

The features of VM7200 can be summarized as (1)high performance-read gain 200 V/N typical-input noise 0.75nV/Hz max-head inductance range 0.2 - 10H-write current range 10 - 40 mA-input capacitance=23 pF max; (2)very low power dissipation 7.5 mW typical in sleep mode; (3)power up/down data protect circuitry; (4)reduced write-to-read recovery time; (5)single power supply= 5V ±10%; (6)fault detect capability; (7)designed for thin-film heads; (8)write unsafe detection; (9)standard schottky - isolated 400 damping resistor (patent pending); (10)available in 2, 4, 6 or 8-channel options .

The absolute maximum ratings of VM7200 are (1)power supply: VCC -0.3V to +7V; (2)write current IW: 60mA; (3)input voltages: digital input voltage VIN: -0.3V to (VCC + 0.3)V, head port voltage VH: -0.3V to (VCC + 0.3)V, WUS pin voltage range VWUS: -0.3V to +6V; (4)output current: RDX, RDY: IO: -10mA, WUS: +12mA; (5)junction temperature: 150°C; (6)storage temperature Tstg: -65°C to 150°C; (7)thermal characteristics, OJA: 16-lead SOIC 100°C/W, 20-lead SOlC 80°C/W, 20-lead SSOP TBD, 28-lead SOIC 75°C/W, 36-lead SOIC 60°C/W.