Icom Ci V Usb Interface Schematic Top Jun 2026

: Since CI-V combines Transmit (TX) and Receive (RX) onto a single wire, a small circuit is needed to bridge the TX and RX pins of the UART chip. 3.5mm Mono Jack

Place 0.1µF ceramic bypass capacitors directly adjacent to the VCC pins of both the USB chip and the digital isolator on the top layer. Top Silkscreen Labeling (Visual Anchors)

For a permanent shack installation, isolating the radio from the PC is paramount. This schematic uses two high-speed optocouplers (such as the 6N137 or 4N35) to bridge the gap safely.

Connect the UART TX pin to the cathode (bar side) of a fast-switching signal diode (e.g., 1N4148 ). Connect the anode to the 3.5mm jack's TIP. icom ci v usb interface schematic top

For decades, Icom has used its proprietary protocol to allow computers and accessories to control their transceivers (e.g., IC-7300, IC-9700, IC-705). While modern radios often include built-in USB ports, older or mid-tier models require an external "CI-V USB interface." This article dissects the top schematic of a typical universal Icom CI-V to USB converter.

Integrating an Icom transceiver with a modern computer requires a CI-V (Computer Interface Five) adapter. Most modern PCs lack native RS-232 serial ports, making a USB-to-CI-V interface essential for digital modes, logging, and remote rig control.

Unlike standard RS-232 serial communication which uses separate Transmit (TX) and Receive (RX) lines, CI-V uses a single bi-directional line for both sending and receiving data. : Since CI-V combines Transmit (TX) and Receive

Keep the cable length between the interface and the radio as short as possible. 3. Drivers and Software Configuration

For a more robust "top-tier" design that prevents data collisions and protects your radio, use an like the 7417 or 7407 . Simple Icom CI-V Interface - QSL.net

Combine the separate TX and RX lines into a single, bi-directional 3.5mm mono line without causing data collisions. The Core Schematic Components This schematic uses two high-speed optocouplers (such as

Unlike standard RS-232 or TTL serial interfaces that use separate Transmit (TX) and Receive (RX) lines, CI-V uses a single bi-directional line for data transfer.

: If building your own, ensure you install the appropriate Virtual COM Port (VCP) drivers from the chip manufacturer (e.g., FTDI ) to allow software like Ham Radio Deluxe or FLDigi to communicate with the rig. Explore USB with this USB to CI-V Interface - N5DUX

USB TTL TxD ---- 10k ----- Base of NPN Emitter - GND Collector ---- 1N4148 ---- CI-V data line | +--- 4.7k pull-up to 5V CI-V data line ---------------------------------------------- USB TTL RxD (with internal pull-up enabled)

The CT‑17 is designed for RS‑232, not USB. It uses a MAX232 or similar chip to convert RS‑232 levels to TTL. Modern homebrew designs replace the RS‑232 portion with a USB‑to‑TTL UART, but the open‑collector bus driver remains essential.