X22 - Bi-directional BNC TTL to Fiber Optic Converter

The X22 is a compact bidirectional TTL to fiber optic converter that moves digital signals in both directions between electrical and optical domains: TTL to fiber, and fiber back to TTL. It runs from an isolated 24VDC supply, so a pair of X22 units provides full high voltage isolation between the TTL signals at each end, and its two independent, switch-selectable polarity controls let you invert either signal path without extra hardware.

The X22 is available in two build options with meaningfully different speed, connectors, and fiber compatibility. The X22-ST-850 uses 850nm ST bayonet fiber connectors, handles frequencies from DC to 50MHz with a propagation delay of 15 nanoseconds or less in each direction, and is compatible with 50/125 μm, 62.5/125 μm, or 200 μm multimode fiber optic cable (62.5/125 μm step index multimode is recommended), making it the right choice when speed and fiber flexibility matter. The X22-VL-650 uses 650nm Versatile Link push-fit connectors, the industry-standard interface for plastic optical fiber, with a propagation delay of 50 nanoseconds or less in each direction; its TTL input impedance is jumper-selectable between high impedance (>1 Mohm) or 50 ohms, useful for matching a wider range of source equipment.

Built with robust components, the X22 ensures reliable performance under challenging operating conditions. It is ideal for a variety of applications, including trigger and logic-level signal delivery, high voltage digital I/O isolation, breaking up ground loops, and extending the range of UART communication signals such as RS232 in large distributed systems.

With optional DIN rail mounting and a compact stainless-steel chassis, the X22 is a versatile choice for various scenarios.

For unidirectional TTL to fiber applications that can drive 30mA, consider the TF1 as a simpler alternative. To fan out fiber optic signals to multiple fiber outputs, the X14 device is recommended.