COM-09 — RS485 fault protection + fail-safe bias
draft · Communication
Statement
The RS485 driver and receiver shall include short-circuit current limiting, thermal-shutdown protection, software TX high-impedance control, and integrated receiver fail-safe bias for predictable behaviour when the bus is idle or reconfigured
Acceptance Criteria
Short-circuit current limiting + thermal shutdown on TX driver (outputs forced to Hi-Z under fault); TX may be placed in Hi-Z by software for multi-drop handoff; receiver fail-safe bias guarantees logic-HIGH output when input pair is left floating; external 1.1 kΩ pull-ups recommended for improved rise-time. Per Sparrow Hardware Datasheet v3 §6.13 (sourceRef: 01_ProductSpec/Sparrow Hardware Datasheet-v3-20260504_150735.pdf)
Sign-offs
No sign-offs recorded. Approving a requirement records one here.