CP2101R

Controllers Overview

The CP2101 is a single-chip USB to UART bridge controller from Silicon Labs, designed to update RS-232 designs to USB with minimal components. It integrates a USB 2.0 full-speed function controller (12 Mbps), transceiver, oscillator, and UART in a 5 x 5 mm MLP-28 package. The device supports baud rates from 300 bps to 921.6 kbps with 512-byte receive and transmit buffers. It includes an on-chip 3.3 V voltage regulator for self-powered operation at 3.0 to 3.6 V or bus-powered operation at 4.0 to 5.25 V. An integrated 512-byte EEPROM allows customization of USB identifiers.

Controllers Feature Summary

• Highly integrated design eliminates the need for external USB components, crystals, or resistors.
• Includes an internal 512-byte EEPROM for programming vendor IDs, product descriptions, and serial numbers via USB.
• Supports all standard modem interface signals including RTS, CTS, DSR, DTR, DCD, and RI.
• Provides royalty-free Virtual COM Port drivers for Windows, Mac OS, and Linux operating systems.

Controllers Applications

• Upgrading legacy RS-232 devices to USB interfaces
• Cellular phone USB interface cables
• PDA USB interface cables
• USB to RS-232 serial adapters

Controllers Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm pinout compatibility and package type. Ensure that any custom EEPROM data requirements are addressed during the manufacturing process using the provided configuration utilities. Confirm that the selected variant meets the required operating temperature range and power supply specifications for the target application environment.

Controllers Selection Notes

Select this component when a compact solution is needed to replace RS-232 level translators without modifying existing firmware. Consider the MLP-28 package dimensions for PCB layout constraints. Verify that the host system can support the required Virtual COM Port drivers. Evaluate whether the integrated 3.3 V regulator provides sufficient current for external circuitry or if an external supply is necessary.

Controllers Part Context

The CP2101 belongs to the classic USB-to-UART bridge family from Silicon Labs. It serves as a foundational component for adding USB connectivity to microcontroller-based systems. Unlike newer models, it lacks high-speed capabilities but offers a proven, low-cost architecture for standard asynchronous serial communication needs in industrial and consumer electronics.

Controllers Replacement Considerations

CP2102: Offers similar functionality with a different package option and slightly higher performance characteristics.

Controllers FAQ

How is the internal EEPROM programmed?

The internal EEPROM is programmed via the USB connection. This allows OEMs to write configuration data, such as Vendor ID and Serial Number, onto the device during the manufacturing and testing process using a stand-alone utility or a Windows DLL library.

What is the maximum baud rate supported by the CP2101?

The CP2101 supports baud rates ranging from 300 bps up to 921.6 kbps. The specific baud rate is configured through the COM port settings on the host PC.

Can the CP2101 operate in both self-powered and bus-powered modes?

Yes. In bus-powered mode, it draws power from the USB VBUS line (4.0 to 5.25 V). In self-powered mode, it operates from an external 3.0 to 3.6 V supply connected to the VDD pin, while still sensing VBUS for connection status.