Silicon Laboratories Inc.

William W K Tang

Axel Thomsen

Ka Yin Leung

Shouli Yan

Zhiwei Dong

Péter Onódy

Michael James Mills

Gerald D Champagne

A method and apparatus for determining an RC (resistive-capacitive) time constant is disclosed. In one embodiment, a method comprises determining a first period of oscillation when an oscillator is operating in a first configuration. The method further comprises determining a second period of oscillation when the oscillator is operating in a second configuration. A measurement circuit is configured to determine a resistive-capacitive (RC) time constant of the oscillator by determining a mean of the first and second periods.

RC calibration using chopping

An integrated circuit having voltage isolation capabilities includes a plurality of communications channels for transceiving data from the integrated circuit. Each of the communications channel includes capacitive isolation circuitry located in conductive layers of the integrated circuit for providing a high voltage isolation link. The capacitive isolation circuitry distributes a first portion of a high voltage isolation signal across a first group of capacitors on a first link and a second link in the capacitive isolation circuitry and distributes a second portion of the high voltage isolation signal across a second group of capacitors in the first link and the second link in the capacitive isolation circuitry. A differential receiver on each of the plurality of communications channels receives the data on the first link and the second link. A differential transmitter on each of the plurality of communications channels transmits the data on the first link at a selected one of a first phase and a second phase and for transmitting the data on the second link at the selected one of the first phase and the second phase. The second phase is 180 degrees out of phase with the first phase. Each of the differential transmitters controls the selection of the first phase and the second phase on each of the first link and the second link such that only the first phase or the second phase is cross coupled onto a selected communications channel from adjacent communications channels.

Capacitive isolation circuitry

An integrated circuit having voltage isolation capabilities comprising a first galvanically isolated area of the integrated circuit containing a first group of functional circuitry for processing a data stream. The first group of functional circuitry located in a substrate of the integrated circuit. Capacitive isolation circuitry located in conductive layers of the integrated circuit provides a high voltage isolation link between the first group of functional circuitry and a second group of functional circuitry connected to the integrated circuit through the capacitive isolation circuitry. The capacitive isolation circuitry includes a differential transmitter for transmitting data in a differential signal to the second group of functional circuitry via the capacitive isolation circuitry. A differential receiver receives data within the differential signal from the second group of functional circuitry via the capacitive isolation circuitry. A detector circuit within the differential receiver detects the received data. The detector circuit monitors the differential signal and generates a first logical output when a voltage generated responsive to the differential signal exceeds a programmable voltage threshold level and generates a second logical output when the voltage generated responsive to the differential signal falls below the programmable voltage threshold level.

Capacitive isolation circuitry with improved common mode detector

Growing community of inventors

Austin, TX, United States of America

William W K Tang