USB isolator with advanced control features
AssigneeAnalog Devices, Inc.
InventorsEric Gaalaas, Mark Cantrell
Life of this patent
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Abstract
A USB-based isolator system conveys USB signals between a pair of galvanically isolated circuit systems and supports controlled enumeration by a downstream device on upstream USB signal lines. The isolator system provides a multi-mode voltage regulator to support multiple voltage supply configurations. The isolator system further provides control systems for each of the isolated circuit systems and provides robust control in a variety of start up conditions. Additionally, the isolator system includes refresh timers and watchdog mechanisms to support persistent operation but manage possible communication errors that can arise between the isolated circuit systems.
Claims9
An isolator device, comprising
- a plurality of isolation devices bridging an isolation barrier between an upstream circuit sub-system and a downstream circuit sub-system,
- each of the upstream circuit sub-system and the downstream circuit sub-system comprising:
- a USB transceiver for exchanging USB signals with respective external components, and
- an isolator transceiver coupled to the respective USB transceiver to exchange signals between the USB transceiver and the isolation devices;
- wherein, for at least one circuit sub-system, the isolator transceiver transmitter includes a pulse generator and a refresh pulse generator to generate pulses in response to an input logic signal and to repeat the generated pulses according to a refresh interval, and
- wherein, for at least the other circuit sub-system, the isolator transceiver receiver includes a watchdog timer to maintain the receiver in a reception state if pulses are received within a watchdog interval.
Dependencies are inferred from the claim text.