Description
The CXA1940N is a Read/Write Amplifier for the thin film head of hard disk drives and designed to handle up to 4-channel heads.

FEATUREs
• Operate on single +5V power supply.
• Low power consumption.
    Read : 95mW
    Write (IW=20mA) : 130mW+IW × 5
    Power save : 5.5mW
• Write current can be varied through an external resistor. Built-in stabilizing circuit provides stable current during voltage and temperature drift.
• Drives up to 4 heads.
• Designed for two-terminal thin-film or MIG heads.
• Built-in power save function.
• Read amplifier emitter follower output featuring 290 times gain (Typ.).
• Built-in Write unsafe detection circuit.
• Built-in supply voltage monitor circuit prohibits incorrect Write during power on or abnormal voltage.
• Built-in IC protection circuit for short of head and GND.
• Differential input capacitance for Read : 14pF (Typ.).
• Write data input minimum pulse width : 10ns
• Read data output become high impedance in write mode to improve read data offset when switching from write to read mode.
• Unselected head DC voltage is GND potential.
• Self switching damping resistance (RD=310Ω)

Function
    Read, Write and Write unsafe detection for HDD, Power supply ON/OFF detection.