Icom Ci V Usb Interface Schematic Top ⚡

CI-V requires an open-collector driver.

Most interfaces are bus-powered from USB. icom ci v usb interface schematic top

Alternatively, a separate isolated DC-DC converter (e.g., B0505S) can generate a floating 5V for the radio side, eliminating the need to draw power from the radio. CI-V requires an open-collector driver

If you are building or buying such an interface, here is what the schematic tells you about performance: Alternatively , a separate isolated DC-DC converter (e

| Requirement | Why it matters | |-------------|----------------| | Open-collector driver (Q1) | CI-V is a shared bus; multiple devices can drive it low. A standard totem-pole output would short-circuit. | | Pull-up resistor (~4.7kΩ) | Ensures CI-V line idle high without current drain. | | Diode protection | Prevents CI-V voltage (5-12V accident) from back-driving FTDI chip. | | No ground loops | The interface should have opto-isolation (advanced) or at least common ground – but a direct ground is acceptable for single radio. | | Inversion as per Icom spec | Without correct inversion, commands will be byte-swapped or corrupt. |

If you prefer a ready-made product, several commercial interfaces appear at the top of search results, including:

However, building from a top-quality schematic gives you complete control over isolation quality, component choice, and cost (under $15).