MxL81108

Enhanced 4-Ch Full-Speed USB UART
PRE (Pre-introduction)

Overview

Information Enhanced 4-Ch Full-Speed USB UART
Data Bus Interface USB 2.0
# of Channels 4
Max Data Rate 5V (Mbps) 12
Max Data Rate 3.3V (Mbps) 12
Tx FIFO (Bytes) 512
Rx FIFO (Bytes) 512
Auto RS-485
Auto Flow Control
Auto Half-Duplex Control
Multidrop (9-bit) Mode
Fractional Baud Rate Generator
Power Down Mode
5V Tolerant Inputs
IrDA Sup
Supply Voltage Range VCC (V) 3.0 to 3.6, 4.4 to 5.25
Max UART/GPIO Input Voltage (V) 5.5
Max UART/GPIO Output Voltage (V) 1.8-3.6
Temperature Range (°C) -40 to 85
Package LGA64
X-Y Dimension (mm) 9x9
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The MxL81108 is an enhanced universal asynchronous receiver and transmitter (UART) bridge to USB interface. The USB interface is fully compliant to the USB 2.0 (full speed) specification with 12Mbps USB data transfer rate. The USB interface also supports USB suspend, resume, and remote wakeup operations. The USB Vendor ID, Product ID, power mode, remote wakeup support, maximum power, and numerous other settings may be programmed in the on-chip OTP memory via the USB interface.


The MxL81108 includes an internal oscillator and does not require an external crystal/oscillator. Any UART baud rate from 300 bps to 12Mbps may be generated with this internal clock and the fractional baud rate generator.


The UART pins for each port may also be configured as GPIO; direction, state, output driver type, and input pull-up or pull-down resistors are programmed either through on chip OTP, or on the fly via memory mapped registers.

Large 512-byte Tx and Rx FIFOs prevent buffer overflow errors and optimize data throughput. Automatic half duplex direction control and optional multi drop (9-bit) mode simplify both hardware and software in half-duplex RS-485 applications. Wide mode allows for each individual received character to be monitored for errors.


The MxL81108 uses the native OS CDC-ACM driver or a MaxLinear supplied custom driver. MaxLinear provides WHQL-certified software drivers for Windows 2000, XP, Vista, 7, 8, 8.1, 10, and 11 as well as custom software drivers for Linux. Full source code is available.


The MxL81108 operates from a single 5V or 3.3V power supply. When powered with 5V input, a regulated 3.3V output is supplied.

  • ±15kV ESD on USBD+/USBD- USB 2.0 Compliant, full-speed (12Mbps)

  • Unique pre-programmed USB serial number

  • Internally generated 48MHz core clock

  • Enhanced UART features

    • Baud rates from 300bps to 12Mbps

    • Fractional baud rate generator

    • 512-byte Tx and 512-byte Rx FIFOs

    • Multi-drop and half-duplex modes

    • Auto RS-485 half-duplex control

    • Selectable GPIO or modem I/O

  • 5V tolerant GPIO inputs

  • Suspend state GPIO configuration

  • Configurable clock output

  • 9mm x 9mm, 64-pin LGA package

  • Industrial temperature range from –40°C to +85°C

  • Data Center Console Access

  • Building automation

  • Security systems

  • Factory and process control

  • ATM Terminals

  • USB to Serial controllers

Documentation & Design Tools

Type Title Version Date File Size
Product Brochures Serial Transceivers & Bridges Brochure R03 May 2025 3.6 MB

Parts & Purchasing

Part Number Pkg Code Min Temp Max Temp Status
MXL81108-AYA-R -40 85 PRE
MXL81108-AYA-EVK-1 Board PRE

Part Status Legend
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.