ENVELOPE DETECTOR ARCHITECTURE WITH NOISE CANCELATION

Organization Name

STMicroelectronics International N.V.

Inventor(s)

Alessio Emanuele Vergani of Milano IT

Francesco Piscitelli of Milano IT

Michele Bartolini of Carpiano IT

ENVELOPE DETECTOR ARCHITECTURE WITH NOISE CANCELATION

This abstract first appeared for US patent application 18480322 titled 'ENVELOPE DETECTOR ARCHITECTURE WITH NOISE CANCELATION

Original Abstract Submitted

According to an embodiment, an envelope detector circuit for detecting an envelope of a signal from a sensor in a pre-amplifier circuit of a hard disk drive is provided. The circuit includes a half-wave rectifier, a low-pass filter, and a differential full-wave rectifier. The half-wave rectifier receives a differential voltage from the sensor indicating a fly height of the hard disk drive and generates a pair of single-ended output waveforms based on the differential voltage. Each pair of single-ended output waveforms has a positive polarity for a half-cycle it passes through. The low-pass filter includes a first and a second low-pass filter. The low-pass filter allows low-frequency signals from the pair of single-ended output waveforms to pass through while attenuating or blocking higher-frequency signals. The differential full-wave rectifier reconstructs a differential signal from the low-pass filter while removing DC rectified components.