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USB-Serial Bridge Controller | Cypress Semiconductor

USB-Serial Bridge Controller

USB-Serial Bridge Controller

Cypress expands the USB Controller product portfolio with the introduction of CY7C6521x, a family of Full-speed USB-Serial Bridge Controllers. These bridge controllers are first in the industry to offer configurable serial channels for UART/I2C/SPI interfaces, with industry’s lowest power consumption in stand-by mode (5 uA). These fixed function controllers can be easily configured to work as USB to UART, USB to I2C, or USB to SPI bridges without requiring any Firmware development by the user.


The USB-Serial bridge controllers integrate the industry-leading CapSense capacitive-touch sensing technology (for touch sensitive key switches) and Battery Charger Detection compliant to USB-IF Battery Charging specification ver. 1.2 (to detect the source of power on the USB port). These controllers are ideal for applications such as portable medical devices (like blood-glucose meters), point-of-sales terminals, Serial Cables (including USB-to-UART and RS232 cables) and many other applications requiring USB connectivity.



For additional product information and support, please email us at

  1. Download the USB-Serial Product Overview
  2. Identify which part suits your needs by visiting the Features tab
  3. Purchase the corresponding USB-Serial Development Kit
  4. Download and install the USB-Serial DVK Setup. The DVK setup includes:
  5. Go through the USB-Serial Knowledge Base Articles
  6. Start your design and get your Schematics reviewed by the Cypress Applications Engineering Team using the Online Tech Support Case System

USB-Serial RDK/DVK kits enable the user to evaluate the features of the USB-Serial Bridge Controllers. The kits are integrated with the required components to perform the evaluation. The software configuration utility can be used to change the parameters of the USB-Serial Bridge Controllers. The kits/controllers are supported with drivers for Windows, Mac, Linux and Android operating systems.

Reference Design Kits

CYUSBS232 - USB-Serial Reference Design Kit (RDK)

CYUSBS232 RDK is a low cost kit to evaluate CY7C65213 USB-UART LP Bridge Controller. The kit along with its hardware documentation serves as a reference design for applications like USB-to-UART cables.

Development Kits

CYUSBS234 - USB-Serial Development Kit (DVK)

CYUSBS234 DVK helps evaluate the features of the Single Channel USB-Serial Bridge Controller, CY7C65211. The DVK provides a copper pad on PCB to test CapSense feature, EEPROMs to test I2C and SPI interfaces, RS232 line driver to test UART interface and a Li-Ion battery charging controller (battery not included) to test the BCD feature.



CYUSBS236 - USB-Serial Development Kit (DVK)

CYUSBS236 DVK helps evaluate the features of the Dual Channel USB-Serial Bridge Controller, CY7C65215. The DVK provides two copper pads on PCB to test CapSense feature, two pairs of EEPROMs to test I2C and SPI interfaces, two RS232 line drivers to test UART interfaces and a Li-Ion battery charging controller (battery not included) to test the BCD feature.


  • USB to UART Cables
  • USB to RS232/RS422 Converters
  • POS Printers and Terminals
  • Medical Devices (e.g., Blood Glucose Meters)
  • Networking System
  • USB Barcode Readers
  • USB Industrial and Power Meters
  • NFC Card Readers
  • Fingerprint Scanners
  • USB Wireless/Wired Modems
  • Servers and Networking Switches
  • Home Gateways
  • USB Smartcard Readers
  • Set Top Boxes
  • GPS dongles
  • Set Top Boxes
  • Smart UPS
  • USB Audio and Low Bandwidth Video data transfer
  • USB MP3 Player Interface
  • USB Software/Hardware Encryption Dongles
  • Precision Trackpad (PTP) bridge
  • KVM Switch
  • AV Splitters
  • RC Toys
  • LCD Modules (LCM)
  • USB-Serial Adapters
  • USB-IF Certified – TID# 40860041
  • Dual Serial Channels for UART/I2C/SPI interfaces
  • UART data rates up to 3 Mbps
  • I2C data rates up to 400 KHz
  • SPI data rates up to 3 MHz
  • Full-Speed USB controller with Integrated termination resistors, voltage regulator, on-chip oscillator and Flash – no external components required
  • Industry leading CapSense® controller – Supports up to 8 touch-sensing buttons
  • Compliant to USB-IF Battery Charging specification ver. 1.2 – Supports SDP (500 mA), CDP (1500 mA) and DCP (1500 mA) charging modes
  • Low current consumption – 5uA (Typ) in Suspend mode and 15mA (Typ) in Active mode
  • Up to 17 GPIOs available to the user (can drive LEDs)
  • Wide supply voltage range – 1.71v to 5.5v
  • USB voltage range – 3.3v to 5.25v
  • Support for bus powered, self powered, and high-power bus powered USB configurations
  • ESD protection: 2.2-kV HBM
  • -40°C to 85°C extended operating temperature range.
  • Easy-to-use Configuration Utility – Configure VID, PID, Product and Manufacturer Descriptors, UART, I2C, SPI, CapSense, BCD, Charger Detection, GPIOs, Power mode
  • Driver Support for Windows, Mac, Android & Linux Operating Systems
  • Available in compact Pb-free, RoHS compliant 28-pin SSOP (10.2mm x 5.3mm), 24-pin QFN (4mm x 4mm) and 32-pin QFN (5mm x 5mm) packages

Some of the industry leading features of USB-Serial Bridge Controller are:

  • Configurable Serial Channels

    USB-Serial bridge controllers are the first in the industry to offer Configurable Serial Channels, allowing the user to select between UART, I2C or SPI interfaces. In the case of dual channel controller, the channels can be independently configured to UART, I2C or SPI interfaces, and simultaneously connect two devices with different serial interfaces.

  • Advanced Feature Support

    Cypress USB-Serial bridge controller family integrates industry-leading CapSense® technology to provide support for touch sensitive buttons. These controllers support up to 8 CapSense® buttons with advance features like SmartSense Auto-Tuning and Water tolerance.

    The USB-Serial bridge controllers have integrated battery-charger detection feature, to identify the type of power source on the USB port: like a USB wall adapter or PC. This feature is compliant to USB-IF Battery Charging specification ver. 1.2. The USB-Serial bridge controllers drive the battery management controller to enable faster battery charging, making the Cypress USB-Serial controllers ideal for portable devices.

  • End-to-end Solution

    USB-Serial controllers do not require programming, the parameters of the controller and serial channels can be modified using an easy-to-use Configuration Utility. Cypress provides software drivers for the following Operating Systems – Windows, Mac, Android and Linux.

The following table captures the feature difference between the 3 parts of the USB-Serial Bridge Controller family

Feature CY7C65213 CY7C65211 CY7C65215
  USB-to-UART Single Channel

(UART, I2C or SPI)
Dual Channel

(UART, I2C or SPI)
Serial channels 1 1 2
Configurable No Yes Yes
UART (3 Mbps) Yes Yes Yes
I2C (400 kHz) No Yes Yes
SPI (3 MHz) No Yes Yes
BCD (BC v1.2) Yes Yes Yes
CapSense buttons None 5 8
GPIOs 8 10 17
JTAG No No Yes
UART pins 8 2/4/6 2/4/6
Industrial temp (-40° C to 85° C) Yes Yes Yes



24-QFN 32-QFN

Cypress provides free USB CDC and USB Vendor Class drivers for USB-Serial Bridge Controllers.

These drivers work with all parts of the USB-Serial Bridge Controller family:

USB to UART Controller- CY7C65213
Single Channel USB-Serial Bridge Controller- CY7C65211
Dual Channel USB-Serial Bridge Controller- CY7C65215

Driver support is available for following Operating Systems:

  • Windows 8.1
  • Windows 8.1 x64
  • Windows 8
  • Windows 8 x64
  • Windows 7
  • Windows 7 x64
  • Windows Vista
  • Windows Vista x64
  • Windows XP
  • Windows XP x64
  • Windows 2000
  • Windows 98
  • Windows Server 2012 R2 x64
  • Windows Server 2012 x64
  • Windows Server 2008
  • Windows Server 2008 R2 x64
  • Windows Server 2008 x64
  • Windows Server 2003
  • Windows Server 2003 x64
  • Linux
  • Mac OS X
  • Mac OS 9
  • Mac OS 8
  • Windows CE
  • Android

Cypress USB-Serial Windows drivers are WHQL certified and when you connect a USB-Serial device to your computer, they should be automatically downloaded by Windows Update. You can also download Windows Drivers for any of the above Operating Systems from the Drivers page. USB-Serial Bridge Controllers work directly with the built-in drivers of Linux, Mac and Android operating systems. SDK (containing libraries, drivers) for developing applications for Windows, Linux, Android and Mac operating systems can be downloaded from the USB-Serial Software page.

If you need assistance on any driver or software, please send an email to

Q1. Are USB-Serial Bridge Controllers available in SAWN package?
Ans: Yes, USB-Serial Bridge Controllers are available in SAWN package.

Q2. Can VCCD pin be used to supply current to other ICs?
Ans: No, VCCD pin cannot be used to supply current to other ICs in the system.

Q3. What are Input and Output IO levels supported by USB-Serial devices?
Ans: USB-Serial devices support LVTTL IO levels for Inputs only. CMOS IO level is supported for both Inputs and Outputs.

Q4. Do USB-Serial devices require external 1.5K pull up resistor on USBDP line?
Ans: No, USB-Serial devices don't require external 1.5K pull up resistor on USBDP line. The pull-up resistor is integrated inside the chip.

Q5. Can the WAKEUP pin on USB-Serial device be left floating?
Ans: No, the WAKEUP pin cannot be left floating since it is an input pin. The default polarity of WAKEUP pin is Active Low. So this pin should be pulled high to VDDD (or VCCIO) domain.

Q6. What is the maximum capacitance that can be present on the VBUS pin of USB-Serial Bridge Controller?
Ans: 10μF