Preamp circuit including a loopback mode for data storage devices

A data storage device preamplifier circuit, comprising:

• a write amplifier having an input and an output;
• a read amplifier having an input and an output;
• and
• a loopback circuit configured to selectively connect the output of the write amplifier to the input of the read amplifier,
• wherein the write amplifier is configured to i) amplify a write signal received from a read channel circuit and ii) output the amplified write signal to a read/write device,
• wherein the read amplifier is configured to i) amplify a read signal received from the read/write device and ii) output the amplified read signal to the read channel circuit, and
• wherein the loopback circuit includes
• at least one of a switch and a multiplexer configured to selectively connect the output of the write amplifier to the input of the read amplifier;
• and
• an attenuation circuit configured to attenuate the output of the write amplifier when the loopback circuit is active.

A read/write path for a data storage device, comprising:

• a read channel circuit;
• a write amplifier configured to amplify a write signal from the read channel circuit and output the amplified write signal to the data storage device;
• a read amplifier configured to amplify a read signal received from the data storage device;
• and
• a preamplifier circuit in communication with the read channel circuit, the preamplifier circuit including
• a loopback circuit comprising at least one of a switch and a multiplexer configured to selectively connect an output of a write amplifier to an input of the read amplifier, and
• an attenuation circuit configured to attenuate the output of the write amplifier when the loopback circuit is active,
• wherein the loopback circuit is in communication with the write amplifier and the read amplifier and is configured to selectively provide a loopback path to test the operation of the write amplifier.

A method for operating a preamplifier circuit having a write signal input and a read signal output, comprising:

• receiving a write signal at the write signal input of the preamplifier circuit;
• amplifying the write signal;
• selectively looping back the write signal to the read signal output;
• attenuating the write signal;
• and
• amplifying the write signal.