Icom - Ci V Usb Interface Schematic Top !!exclusive!!
These circuits can be "port-powered" using the RTS or DTR lines, or powered externally with a 5V regulator like the Critical Specs for Your Build Signaling: 1-wire bidirectional TTL ( ); data line is when idle. Baud Rate:
When the USB device talks, it pulls the single wire low via the diode. When the radio talks, it pulls the wire low, and the signal reaches the RXD pin. 3. Top Commercial CI-V Interfaces (Ready-Made)
Connect the anode of the directly to the 3.5mm Jack Tip . Connect VCC_RIG to the anode (Pin 2) of IC 3 through a 330 Ωcap omega resistor (R2).
A direct connection uses a simple USB-to-TTL serial adapter directly connected to the radio. While cheap, this creates a direct electrical path between your computer’s switching power supply and your sensitive HF transceiver. This often introduces significant USB ground loop noise (RFI) into your receiver and risks damaging equipment if a voltage differential occurs.
, or chips). These modules provide separate TX (Transmit) and RX (Receive) pins, which must be combined into the single-wire CI-V bus. Simple Diode/Resistor Circuit icom ci v usb interface schematic top
Before looking at the schematics, it is crucial to understand how CI-V works.
Follow these step-by-step pin connections to assemble the interface on a prototyping board or custom PCB. Step A: Wiring the PC Side (USB Domain)
By following the N5DUX or G3VGR schematics, you can build a highly effective interface, saving money and gaining a deeper understanding of your Icom radio.
This is the most reliable, cleanest, and most popular design for modern ham shacks. It utilizes a dedicated USB-to-TTL breakout board (such as an FTDI FT232RL, CP2102, or CH340G) and a single switching diode to combine the lines. The Schematic Circuit: These circuits can be "port-powered" using the RTS
If you need help choosing software for or logging ?
Because PCs no longer feature native serial ports or raw TTL pins, we must convert USB data into a single-wire TTL format. Technical Block Diagram A reliable DIY interface consists of three core stages:
Below are the two most popular schematics used by radio amateurs. The first is a simple, non-isolated circuit for quick builds. The second is a studio-grade, fully isolated circuit designed for permanent station integration. Option A: The Simple Diode-Mixed Circuit (Non-Isolated)
For those interested in learning more about the ICOM CI-V USB interface schematic, here are some top resources: A direct connection uses a simple USB-to-TTL serial
Beginners and those who want a reliable, compact build inside a USB cable or small box. Common Chips: FTDI FT232RL, CH340G, CP2102.
Modern operating systems (Windows 10/11, macOS, Linux) usually install FTDI drivers automatically. If not, download the latest VCP (Virtual COM Port) drivers from the official FTDI website.
| Approach | Key Components | Typical Use Case | | -------------------------------- | --------------------------------------- | ------------------------------- | | | 2N2222A, 2N3904, resistors, diodes | Older designs with native COM port | | MAX232 chip (RS-232) | MAX232, capacitors, DTR/RTS power | Direct replacement for CT-17 | | USB‑to‑TTL + buffer | FTDI chip or CP210x, 7417 buffer | Modern USB-native solution |
A 3.5mm mono plug connects to the radio's "REMOTE" jack; the tip is data, and the sleeve is ground. Transistor-Based Level Shifter
The most efficient DIY design uses a common USB-to-Serial board (like those based on , CP2102 Go to product viewer dialog for this item.