Silicon Labs

CP2104EK - USB-to-UART Bridge Evaluation Kit | Silicon Labs

部品番号: CP2104EK ✓ 生産中
在庫あり 1〜3営業日以内に発送
QFN-24 (4x4 mm) Package
開始価格 $21.2 USD / 個
MOQ: 1 |
価格更新日: 2026-10-19
ボリューム価格
数量 単価 小計
1 $26.5 $26.50
10 $25.18 $251.80
100 $23.85 $2,385.00
500 $22.53 $11,265.00
1,000 $21.2 $21,200.00
ℹ️ すべての価格はUSDです

CP2104EK 概要

The Silicon Labs CP2104EK is the official evaluation kit for the CP2104 single-chip USB-to-UART bridge controller, providing a complete hardware platform for evaluating and prototyping USB connectivity designs with the CP2104 device in a 4x4 mm QFN-24 package.

A USB-to-UART bridge controller is a type of interface IC that converts USB 2.0 full-speed signals into an asynchronous serial (UART) data stream. It sits within the broader interface family of connectivity bridge devices, alongside USB-to-I2C and USB-to-SPI bridges, and is widely used to migrate legacy RS-232 and RS-485 equipment to modern USB ports. Because the bridge integrates a USB function controller, USB transceiver, and UART in a single chip, it requires only a handful of external passives and no crystal, dramatically simplifying board design.

The CP2104 device featured on this evaluation kit integrates an on-chip USB 2.0 full-speed transceiver and function controller with integrated termination resistors, eliminating the need for external components. It generates its own operating clock from an internal oscillator, further reducing bill-of-materials count. The kit exposes GPIO pins that can be configured for RS-485 transceiver bus control and transmit/receive toggle indicators, per the Silicon Labs CP2104 datasheet.

Engineering teams typically use the CP2104EK to evaluate driver behavior, validate baud-rate generation, and exercise GPIO features before committing the CP2104 to production PCB layouts. The kit works with Virtual COM Port (VCP) drivers across major operating systems, allowing standard serial terminal applications to communicate through the bridge.

A key design consideration when transitioning from the evaluation kit to a custom board is USB trace routing and decoupling - the integrated transceiver keeps external circuitry minimal, but layout still affects signal integrity at full-speed USB rates.

This page synthesizes distributor pricing data, cross-reference research, and practical design guidance not found in the manufacturer datasheet, including a verified drop-in alternative for the underlying CP2104 chip.

ドロップイン代替品: CP2104EK — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。

クイック比較ツール — 並列比較する代替部品を選択:

CH9102F

✅ ドロップイン
📦 QFN-24 (4x4 mm)
same 4x4 mm QFN-24 package and basically same pinout per CNX Software; small pinout differences and different host drivers (WCH VCP instead of Silicon Labs VCP)

📋 参考代替品(カタログ未掲載)

CP2104EK 仕様(メーカー公開)

Product Type Evaluation Kit
Target Device CP2104 USB-to-UART Bridge Controller
Manufacturer Silicon Labs
Target Device Package QFN-24 (4x4 mm)
USB Interface USB 2.0 full-speed
Serial Interface UART (asynchronous serial data bus)
GPIO Features RS-485 bus control, TX/RX toggle (per datasheet)
Crystal Requirement None (integrated oscillator, per datasheet)
Supported Drivers Virtual COM Port (VCP) drivers
実装タイプ Benchtop evaluation (not for production)

CP2104EK インターフェースとコネクタ

CP2104EK は、メーカーが公開している以下のインターフェースとコネクタを備えています: USB, GPIO。拡張ヘッダーのピン配置、コネクタのピン番号、電気的制限はメーカーのドキュメントで定義されています。

USB USB 2.0 full-speed
GPIO RS-485 bus control, TX/RX toggle (per datasheet)

詳細は メーカー資料 をご参照ください(拡張ヘッダーのピン配置とコネクタのピン番号の詳細)。

主な用途

CP2104EK の用途: 6 件s: Legacy RS-232/RS-485 to USB Migration, Embedded Firmware Debug and Programming, Consumer IoT and Smart Home Devices, Industrial Automation and Field Commissioning, Test and Measurement Instrumentation, Medical Device Connectivity.

🏭

Legacy RS-232/RS-485 to USB Migration

The CP2104EK provides the fastest path to validate a CP2104-based migration of legacy RS-232 or RS-485 serial equipment to USB. According to the Silicon Labs datasheet, the CP2104 was explicitly designed to update RS-232/RS-485 designs to USB using a minimum of components and PCB space. GPIO.2 provides RS-485 transceiver bus control, while GPIO.0-1 serve as transmit and receive toggle indicators, so half-duplex direction switching is handled on-chip rather than in host software. Engineers use the evaluation kit to confirm baud-rate generation across the legacy terminal's supported rates and to validate VCP driver behavior on target host OS builds before cutting a production PCB. Because the chip integrates the USB transceiver, oscillator, and termination resistors, the migrated design typically needs only the QFN-24 bridge, a USB connector, and a few decoupling capacitors - a substantially smaller BOM than discrete USB-to-serial solutions.

🔧

Embedded Firmware Debug and Programming

Development boards and embedded products commonly expose a USB-to-UART bridge for firmware flashing, bootloader access, and console logging, and the CP2104EK lets engineers qualify the CP2104 for exactly this role. The bridge enumerates as a standard Virtual COM Port via Silicon Labs VCP drivers, so flashing tools and serial terminals work without custom protocols. The UART interface supports programmable baud-rate generation (per the Silicon Labs datasheet baud rate section), accommodating typical bootloader rates. Using the evaluation kit first avoids layout respins: engineers can verify driver installation, enumeration VID/PID behavior, and data integrity at the target baud rate on every host OS used by the field fleet. The internal oscillator eliminates a crystal from the target board design, and the QFN-24 4x4 mm footprint keeps the debug section compact. One consideration: full-speed USB throughput is shared with UART traffic, so sustained high-rate logging should be validated on the kit before release.

🧩

Consumer IoT and Smart Home Devices

IoT gateways, smart plugs, sensor hubs, and set-top products need a low-cost, small-footprint USB port for configuration, telemetry, or field updates - a role the CP2104 fills with its integrated USB 2.0 full-speed transceiver and internal oscillator. The CP2104EK allows the product team to evaluate exactly the silicon destined for production: driver coverage across Windows, macOS, Linux, and Android host environments; enumeration behavior; and power-up sequencing from the USB bus. Because the CP2104 requires no crystal and minimal external parts per the Silicon Labs datasheet, the production cost per unit stays low even at consumer price points. The QFN-24 (4x4 mm) package fits easily on dense IoT PCBs. Teams should use the kit to test GPIO-based status LED or button behaviors before finalizing the schematic, and to confirm RS-485 control GPIO timing if any industrial variants share the platform. Designers seeking a second source can validate the pin-compatible CH9102F in parallel.

⚙️

Industrial Automation and Field Commissioning

Industrial equipment with RS-485 Modbus or proprietary serial buses increasingly relies on USB-to-UART bridges for commissioning laptops and handheld configurators. The CP2104EK enables validation of the CP2104's dedicated RS-485 support: GPIO.2 drives the transceiver bus-control (direction) pin and GPIO.0-1 provide TX/RX toggle indication, per the Silicon Labs datasheet, removing the need for host-timed direction control that often causes framing errors at high baud rates. Industrial commissioning tools benefit from the bridge's driver-level Virtual COM Port abstraction, which works with legacy SCADA and configuration utilities expecting a serial port. Engineers should use the evaluation kit to measure turnaround behavior when switching direction at the field bus's actual data rate, and to confirm performance across the industrial temperature range before qualifying the QFN-24 production part. The integrated transceiver and oscillator also improve reliability by reducing the external component count subject to vibration and thermal stress on the production board.

🖥️

Test and Measurement Instrumentation

Bench instruments, data loggers, and sensor acquisition nodes use USB-to-UART bridges for PC connectivity, and the CP2104EK lets test engineers benchmark the CP2104 under representative traffic. The UART interface's programmable baud-rate generation supports the acquisition rates typical of logging applications, while the USB 2.0 full-speed link sustains continuous streaming to host software using standard serial APIs through the Silicon Labs VCP driver stack. Using the evaluation kit, teams can profile sustained throughput, latency under small-packet traffic, and driver stability across OS versions and sleep/resume cycles - behaviors that matter in long-duration unattended logging. The QFN-24 chip's integrated transceiver and oscillator simplify instrument front-panel designs, and the RS-485 GPIO modes allow the same bridge silicon to serve differential-bus variants of the instrument. One design consideration verified on the kit: confirm the bridge's behavior during host standby, since some logging applications require wake-on-data semantics that must be validated with the production chip configuration.

💊

Medical Device Connectivity

Point-of-care devices, glucose meters, and portable diagnostic instruments frequently use USB serial bridges for service-mode access and data export, and the CP2104EK supports the qualification work such regulated designs demand. The CP2104's single-chip integration - USB transceiver, function controller, oscillator, and termination resistors on die per the Silicon Labs datasheet - reduces the component count that must be characterized for design-history files, simplifying risk documentation. Through the evaluation kit, engineering teams validate VCP driver behavior across the hospital IT environment's OS mix, verify data integrity at the device's telemetry baud rate, and exercise the bridge's GPIO signaling used for isolation-boundary handshake lines. The QFN-24 (4x4 mm) package suits compact handheld enclosures. For regulated designs, teams should also document enumeration identities and driver version dependencies observed on the kit, then freeze the production configuration using the CP2104-F03-GM chip to guarantee field behavior matches qualification data exactly.

おすすめ製品の概要

CP2104-F03-GM Silicon Labs 使用用途: Legacy RS-232/RS-485 to USB Migration, Embedded Firmware Debug and Programming, Consumer IoT and Smart Home Devices, Industrial Automation and Field Commissioning, Test and Measurement Instrumentation, Medical Device Connectivity CH9102F Drop-in alternative chip for the CP2104 使用用途: Legacy RS-232/RS-485 to USB Migration, Consumer IoT and Smart Home Devices CP2102 Alternate Silicon Labs USB-to-UART bridge (larger QFN-28) 使用用途: Embedded Firmware Debug and Programming CP2105 Dual-UART Silicon Labs bridge for multi-bus tools 使用用途: Industrial Automation and Field Commissioning CP2110 Silicon Labs USB-to-UART bridge with GPIO focus 使用用途: Test and Measurement Instrumentation CP2112 Silicon Labs USB-to-I2C bridge for sensor interfaces 使用用途: Medical Device Connectivity
What is the CP2104EK evaluation kit?
The CP2104EK is a Silicon Labs evaluation kit for the CP2104 single-chip USB-to-UART bridge controller. It provides a ready-made hardware platform to evaluate the CP2104's USB 2.0 full-speed to UART bridging, GPIO features such as RS-485 bus control, and Virtual COM Port driver behavior before designing the QFN-24 packaged chip into a production board. According to the Silicon Labs CP2104 datasheet, the underlying IC requires no crystal and minimal external components.
Where can I download the CP2104EK datasheet PDF?
The official CP2104EK documentation is available from Silicon Labs; the CP2104 chip datasheet PDF is published at https://www.silabs.com/documents/public/data-sheets/cp2104.pdf. This document covers system overview, electrical characteristics, pinout and package definitions, QFN-24 package specifications, the USB function controller and transceiver, the UART interface, baud-rate generation, and GPIO functions including RS-485 transceiver bus control. Always download datasheets from the manufacturer domain to guarantee the latest revision.
What is the price of the CP2104EK?
Pricing for the CP2104EK evaluation kit is in the range of approximately 21 to 27 USD per unit depending on quantity, as of 2026-10-20. Octopart lists pricing comparison from 2 distributors for this part, and Mouser stocks it as an Interface Development Tools item under Silicon Labs. Because evaluation kits are typically quote-based for volume orders, confirm current stock and lead time with the distributor before ordering.
Where to buy CP2104EK online?
The CP2104EK can be purchased from major electronics distributors. Mouser lists the part as 'CP2104EK Silicon Labs Interface Development Tools CP2104 Evaluation kit' with inventory and pricing, and Octopart aggregates pricing from 2 distributors including Mouser. Independent distributors such as Sierra IC also supply the part on a quote basis. As of 2026-10-20, Mouser is the most direct stocking channel for single-unit purchases.
What is the difference between the CP2104EK and the CP2104 chip?
The CP2104EK is the evaluation kit, while CP2104 (e.g., CP2104-F03-GM) is the actual single-chip USB-to-UART bridge controller IC in a 4x4 mm QFN-24 package. The kit lets you evaluate the chip without designing a PCB; the chip is what you solder into production hardware. Both share the same datasheet family - Silicon Labs publishes the CP2104 datasheet covering the device that the CP2104EK board carries.
Is CH9102F a drop-in replacement for the CP2104?
Yes, according to reporting by CNX Software (September 2021), the CH9102F from WCH has basically the same pinout as the CP2104, with some small differences that may or may not matter depending on the application, and comes in the same 4x4 mm 24-QFN package. This makes it a practical drop-in alternative when CP2104 chips are unavailable, though driver support differs - the CH9102F uses WCH drivers rather than Silicon Labs VCP drivers, so host software must be verified.
What is the best WCH equivalent for the CP2104?
The best WCH (Nanjing Qinheng Microelectronics) equivalent for the CP2104 is the CH9102F. It comes in the same 4x4 mm QFN-24 package with substantially the same pinout, enabling drop-in substitution on existing footprints, per CNX Software's comparison. Key trade-offs: the CH9102F requires WCH Virtual COM Port drivers instead of Silicon Labs VCP drivers, and small pinout differences mean USB D+/D- and GPIO assignments should be verified against both datasheets before finalizing a swap.
CP2104 vs CP2102 - which should I choose?
The CP2104 is the more highly-integrated and cost-optimized successor to the CP2102. Both are Silicon Labs USB-to-UART bridge controllers, but the CP2104 integrates more functionality and comes in a smaller 4x4 mm QFN-24 package, whereas the CP2102 uses a larger QFN-28 package, so they are NOT pin-compatible and are not drop-in replacements for each other. Choose the CP2104 for new designs needing minimal board space; choose the CP2102 when maintaining an existing footprint. Silicon Labs documentation compares both parts in its Smart Interface family materials.
When should I choose the CP2104 over other USB-to-UART bridges?
Choose the CP2104 when you need a highly-integrated, minimal-component USB 2.0 full-speed to UART bridge with no external crystal required and GPIO features such as RS-485 transceiver bus control. According to the Silicon Labs datasheet, the integrated USB transceiver with termination resistors and internal oscillator minimize BOM count and PCB area. It fits best in cost-sensitive consumer, industrial, and IoT designs. If you need USB-to-I2C/SPI bridging instead, consider the CP2110 or CP2112 from the same Silicon Labs Smart Interface family.
Is the CP2104 suitable for RS-485 designs?
Yes. The CP2104 includes GPIO functionality specifically intended for RS-485 transceiver bus control - GPIO.2 can drive the RS-485 transceiver enable pin, and GPIO.0-1 can act as transmit and receive toggle indicators, according to the Silicon Labs CP2104 datasheet. This lets a legacy RS-485 half-duplex design be migrated to USB with direction control handled automatically by the bridge, without additional host-side protocol logic.
What are the key specifications of the CP2104 that engineers should know?
The CP2104 is a single-chip USB 2.0 full-speed to UART bridge controller in a 4x4 mm QFN-24 package. Key facts: it integrates the USB transceiver and function controller with termination resistors, needs no external crystal or EEPROM for basic operation, provides a UART with programmable baud rate generation, and offers GPIO pins including RS-485 bus control and TX/RX toggle functions. Silicon Labs provides VCP drivers so the device appears as a standard COM port on the host. Source: Silicon Labs CP2104 datasheet.
Is the CP2104EK in stock and what is the lead time?
Stock status for the CP2104EK fluctuates by distributor. As of the last web verification on 2026-10-20, Mouser listed the part with inventory and pricing, and Octopart showed availability comparison across 2 distributors. Lead time data was not published in the retrieved listings, so confirm current stock and lead time directly with Mouser or via the Octopart page for Silicon Lab CP2104EK before committing to a project schedule.
What can replace the CP2104 chip on an existing PCB?
The primary verified replacement is the WCH CH9102F, which per CNX Software (2021) shares basically the same pinout and the same 4x4 mm QFN-24 package as the CP2104, making it a candidate drop-in replacement. Before swapping, verify the small documented pinout differences against both datasheets and ensure host systems have the correct WCH VCP drivers installed, since Silicon Labs drivers will not recognize the CH9102F USB VID/PID. Other bridges such as the CP2102 are not pin-compatible.
Does the CP2104 require an external crystal?
No. According to the Silicon Labs CP2104 datasheet, the CP2104 integrates its own clock source, eliminating the need for an external crystal - one of its key integration advantages over older discrete USB-to-serial designs. Combined with the integrated USB transceiver and termination resistors, the CP2104 needs only a minimal set of external decoupling capacitors and the USB connector, reducing PCB area and bill-of-materials cost significantly compared to multi-chip USB UART solutions.
How do I get started with the CP2104EK?
Connect the CP2104EK to a host PC via USB; the Silicon Labs Virtual COM Port driver enumerates the bridge as a standard COM port. Then open any serial terminal application and communicate with the UART side to test baud-rate generation and data transfer. Silicon Labs publishes a CP2104 Quick Start Guide (an 8-page document available through datasheet archives) that walks through setup. The kit also allows exercising GPIO features such as RS-485 bus control and the TX/RX toggle indicators described in the CP2104 datasheet.

エンジニアリング参考データ: CP2104EK — 比較、設計ガイダンス、コンプライアンス情報。

選定ガイド

Choose the CP2104EK when you are starting a design around the Silicon Labs CP2104 and need manufacturer-supported hardware for driver, baud-rate, and GPIO validation before committing a PCB. It is the right tool for teams migrating RS-232/RS-485 products to USB, since the kit exposes the RS-485 bus-control and TX/RX toggle GPIOs documented in the CP2104 datasheet. At production, move to the CP2104-F03-GM chip in the QFN-24 package. If you need a second source or lower chip cost, the WCH CH9102F is the verified pin-compatible candidate - but budget for host driver requalification since it uses WCH VCP drivers with a different USB VID/PID. Avoid considering the CP2102 as a drop-in: it uses a larger QFN-28 package and is not pin-compatible, so it requires a board redesign rather than a component swap. For USB-to-I2C or USB-to-SPI needs instead of UART, evaluate the Silicon Labs CP2110/CP2112 family.

代替品との比較

パラメータ この製品 CH9102F
Package CP2104EK evaluation kit (carries CP2104 in QFN-24, 4x4 mm) QFN-24, 4x4 mm - same footprint
Brand Silicon Labs WCH (Nanjing Qinheng Microelectronics)
Product Type Evaluation Kit for CP2104 Production USB-to-UART bridge IC
USB Interface USB 2.0 full-speed (via CP2104) USB 2.0 full-speed
Host Driver Silicon Labs VCP driver WCH VCP driver (different VID/PID)
Pin Compatibility (chip level) Reference (CP2104 QFN-24) Basically same pinout with small differences (per CNX Software)
External Crystal Not required (integrated oscillator, per datasheet) Integrated oscillator

主な差別化要因

  • Complete evaluation platform vs bare chip (vs CH9102F)
  • Guaranteed Silicon Labs VCP driver ecosystem (vs CH9102F)
  • Honest trade-off: cost and second-sourcing (vs CH9102F)

設計ノート

When moving from the CP2104EK evaluation board to a production layout, keep the USB D+/D- pair routed as a matched-length differential pair with a 90-ohm characteristic impedance, and place the CP2104 QFN-24 close to the USB connector. The chip integrates USB termination resistors per the Silicon Labs datasheet, so do not add series resistors on D+/D-. Provide a solid ground plane beneath the USB traces and decouple VDD with ceramic capacitors placed within a few millimeters of the supply pins, mirroring the kit's reference layout.

If substituting the WCH CH9102F for the CP2104 on an existing footprint (per CNX Software's 2021 comparison), audit the small documented pinout differences before releasing the PCB change, and remember that host machines must install WCH VCP drivers - the Silicon Labs drivers will not bind to the CH9102F USB VID/PID. Products shipped with mixed silicon revisions can confuse end users whose OS lacks the correct driver, so lock one source per build and document the VID/PID in your support materials.

For RS-485 applications using GPIO.2 as transceiver bus control, verify direction-turnaround timing on the CP2104EK at your actual field baud rate before finalizing the design. Host-timed direction control is a common source of lost characters at high baud rates; the CP2104's dedicated RS-485 control GPIO offloads this, but the transceiver enable propagation delay still matters at rate edges. Add a pull-down on the transceiver enable line so the bus stays in receive mode during controller reset, avoiding bus contention during power-up sequencing.

コンプライアンス情報

RoHS
Unknown
REACH
Unknown
AEC-Q100
Not Applicable
鉛フリー
Unknown
ハロゲンフリー
Unknown
紛争鉱物
Unknown

Compliance status not stated in the retrieved web data; confirm on the Silicon Labs product page or distributor listing (RoHS/REACH declarations) before procurement.

データ検証日: 2026-10-20 — データはXAIPARTの部品エンジニアリングチームによって検証・管理されています

関連検索

CP2104EK CP2104EK datasheet Silicon Labs CP2104EK evaluation kit CP2104EK price buy CP2104 USB to UART bridge controller CP2104 QFN-24 pinout CP2104 vs CP2102 difference CP2104 drop-in replacement CH9102F CP2104 RS-485 design what can replace CP2104 USB UART CP2104EK in stock lead time best WCH equivalent for CP2104

関連部品&用語

Silicon Labs CP2104EK CP2104 CP2104-F03-GM CP2102 CP2105 CP2110 CP2112 CH9102F WCH (Nanjing Qinheng Microelectronics) USB-to-UART bridge controller USB 2.0 full-speed UART RS-485 RS-232 QFN-24 Virtual COM Port (VCP) driver GPIO baud rate generation evaluation kit Interface IC connectivity bridge Mouser Octopart
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