MCP2221 USB 2.0 to I2C/UART Protocol Converter with GPIO

1 2014-2017 Microchip Technology 1 MCP2221 FeaturesUniversal Serial Bus (USB) Supports Full-Speed USB (12 Mb/s) Implements USB Protocol Composite Device: - Communication Device Class (CDC) for USB-to-UART Conversion- Human Interface Device (HID) for I2C Device Control and Configuration 128-Byte Buffer to Handle Data Throughput at Any Supported UART Baud Rate:- 64-Byte Transmit- 64-Byte Receive Human Interface Device (HID) for Both I2C Communication and Control:64-Byte Buffer to Handle Data Throughput at Any I2C Baud Rate Fully-Configurable VID and PID Assignments and String Descriptors Bus-Powered or Self-Powered USB : TID# 40001594 USB Driver and Software Support Enumerates as a Composite USB Device (CDC and HID) Using Standard Drivers for Virtual Com Port (VCP) on the Following Windows Operating Systems.

2 XP (SP3), Vista , 7, 8 and Configuration Utility for Establishing a Custom Boot-Up Configuration I2C/SMBus Terminal Windows DLLCDC and Universal Asynchronous Receiver/Transmitter (UART) Options Communications Device Class (CDC) for the USB-to-UART Option Responds to SET LINE CODING Commands to Dynamically Change Baud Rates Supports Baud Rates: 300-115200 UART TX and RX Pins Only Serial Number Used During the CDC Enumeration Can Be Enabled by Using the Microchip-Provided Configuration Utility or by Calling the Proper API from the Support Libraries for this DeviceI2C/SMBus The Device Runs as an i2c master .

3 The Data to Write/Read on the I2C Bus is Conveyed by the USB Interface i2c master - Up to 400 kHz Clock Rate- Supports 7-Bit or 10-Bit Addressable Devices; 10-Bit Addressable Devices are Supported through the PC Host Library- Supports Block Reads/Writes of up to 65,535 Bytes SMBus master - Supports All of the SMBus Transfers- SMBus Functionality Is Achieved through a Combination of Chip and Support Library Processing- Up to 400 kHz Clock RateGeneral-Purpose Input/Output (GPIO) Pins Four General-Purpose Input/Output Pins All GP Pins Can Be Assigned to Other FunctionalitiesOther Functionalities UART Activity LED Outputs (UTX and URX)

4 SSPND Output Pin USBCFG Output Pin (Indicates When the Enumeration Has Completed) Three ADC Inputs One DAC with Two Possible Output Options Clock Reference Output: 12 MHz or Other Configurable Values External Interrupt Edge DetectionOther Operating Voltage: to Electrostatic Discharge (ESD) Protection: > 4 kV Human Body Model (HBM) Industrial (I) Operating Temperature: 40 C to +85 C Automotive AEC-Q100 QualifiedUSB to I2C/UART Protocol Converter with GPIOMCP2221DS20005292C-page 2 2014-2017 Microchip Technology TypesBlock DiagramD-D+VSSVDDMCP2221 PDIP/SOIC/TSSOP1234567141312111098 VUSBRSTURXUTXGP2GP3 SDASCLMCP22214 x 4 QFN*12435678910111213141516 EPVDDNCUTXGP2GP3 SDASCLVUSBD-D+VSSNCGP1GP0 URXRSTGP1GP017* Includes Exposed Thermal Pad (EP).

5 See Table HIDUSB CDCCONFIGI2C MasterUARTBUS MATRIXGPIOADC/DACUSBBusI2 CBusTXD/RXDGP PinsPIN MUXIOCCLKRI nternalOscillatorUSB Module & Transceiver 2014-2017 Microchip Technology DESCRIPTIONThe MCP2221 is a USB-to-UART serial Converter thatenables USB connectivity in applications that haveUART and/or I2C interfaces. The device reducesexternal components by integrating the USBtermination resistors and the oscillator needed for USBoperation. The MCP2221 has four GP pins for miscellaneousfunctionalities (including GPIO, USBCFG, SSPND,Clock Output, ADC, DAC and interrupt detector).

6 See Table 1-1 and Section Pin Mux Module fordetails about the pin 1-1:PINOUT DESCRIPTION PinNamePDIP, SOIC,SSOPQFNPinTypeStandard FunctionAlternate FunctionsGP021I/O General purpose I/O or alternate function pinSSPND (OUT)LED_URX (OUT) Signals when the host has entered Suspend modeUART RX LED activity output (factory default)GP132I/O General purpose I/O or alternate function pinCLKR (OUT)ADC1 (IN)LED_UTX (OUT)IOC (IN) Clock Reference OutputADC Channel 1 UART TX Led activity output (factory default)External interrupt edge detectorRST43 IReset input (with internal pull-up)

7 N/AURX54 IUART RX pin (input)N/AUTX65 OUART TX pin (output)N/AGP276I/O General purpose I/O or alternate function pinUSBCFG (OUT) ADC2 (IN) DAC1 (OUT) USB device configured status (factory default)ADC Channel 2 DAC Output 1GP387I/O General purpose I/O or alternate function pinLED_I2C (OUT)ADC3 (IN) DAC2 (OUT) USB-I2C traffic indicator (factory default)ADC Channel 3 DAC Output 2 SDA98I/OI2C Data lineN/ASCL109I/OI2C Clock lineN/AVUSB1110 USB USB Power pin (internally connected to ) Should be locally bypassed with a high-quality ceramic capacitorD-1211 USB USB D-D+1312 USB USB D+VSS1413 PGroundNC 14 15 Not ConnectedVDD116 PPowerEP 17 Exposed Thermal Pad (EP)Do not electrically 4 2014-2017 Microchip Technology Operating SystemsThe following operating systems are supported: Windows XP (SP3), Vista, 7, 8 and Linux any distribution with support for CDC and HID classes Mac OS all versions beginning with MCP2221 enumerates as a composite USB deviceafter Power-on Reset (POR).

8 The device enumeratesas both a Human Interface Device (HID) for I2C, GPIO control, and as CDC for the USB-to-UART HIDThe MCP2221 enumerates as an HID, so the devicecan be configured, while the I2C and GPIO can becontrolled. A DLL package, with example applicationsand tools, is supplied by Microchip on the device webpage on the Microchip web site, CDCThe CDC enumeration implements the USB-to-UART data ModuleThe Bus-Matrix module is the heart of the other modules are tied together and controlled viathe Bus-Matrix module.

9 This module manages the datatransfers between the USB and the UART, the I2 CMaster module, as well as the command requestsgenerated by the USB host controller and commandsfor controlling the function of the UART, GPIO, ADC,DAC and Clock control module interfaces to the UART and THE DEVICEThe MCP2221 can be accessed for reading and writingvia USB host commands. The device cannot beaccessed or controlled via the UART InterfaceThe MCP2221 UART interface consists of the TX andRX data UART is configurable for several baud rates.

10 Theavailable baud rates are listed in Table LINE CODINGThe GET_LINE_CODING and SET_LINE_CODING commands are used to read and set the UART parameters while in operation. For example, terminalapplications ( , Putty, RealTerm, Hyperterminal,etc.) send the SET_LINE_COMMAND when connectingto the port. The MCP2221 responds by setting the baudrate other parameters (Data Bits, Parity, Stop Bits)remain ErrorsPrimary baud rate settings (with associated roundingerrors) are shown in Table baud rates other than the ones shown in the table areused, the error percentage can be calculated usingEquation 1-1 to find the actual baud 1-1:SOLVING FOR ACTUAL BAUD BAUD RATESC ustom baud rates are configured by sending theSET_LINE_CODING USB command.