Industry Smallest Package UART with 2.25V to 5.5V Operation, Intel/Motorola Data Bus Interfaces Select and Exclusive PowerSave Feature

  • Small 32-QFN Package of 5x5x0.9mm
  • Wide Range Supply Voltage Operation of 2.25V to 5.5V
  • Intel/Motorola Data Bus Select
  • PowerSave Reduces Sleep Mode Current down to 30uA*
  • Automatic RTS/CTS Hardware Flow Control
  • Automatic Xon/Xoff software flow control
  • 16-byte Transmit/Receive FIFO to Reduce Bandwidth Requirements of External CPU
  • Wireless Infrared Encoder and Decoder
  • Full Modem Interface (TXD, RXD, RTS, CTS, DTR,DSR, RI, CD)
  • Pb-Free, RoHS Compliant Versions Offered

  • Handheld Appliances
  • Battery Operated Instruments
  • Portable Appliances
  • CDMA Cellular Phones
  • Cellular Base Stations
  • Telecommunications Network Routers
  • Industrial Automation Controls

This dual-channel product family is highly integrated and built for small board space, low voltage and high bandwidth requirements found in a variety of handheld and battery operated applications. These include Point-of-Sale (POS) terminals, tablets and notepads, CDMA cellular phones, expansion modules, instrumentation, cellular base stations, wireless infrared appliances, and industrial automation controls.

The series consists of four devices: XR16L2450, XR16L2550, XR16L2551 and XR16L2552. Each has two independently controlled UART channels and operates over a broad range power source of 2.25V to 5.5V with 5V tolerant inputs.

The XR16L2551 uniquely offers a very small 32-QFN, 5x5x0.9mm, package with PowerSave feature to conserve power down to less than 30uA* of current consumption. These attributes are a perfect combination for tight space and/or battery operated designs. The PowerSave feature eliminates the need for two external octal transceivers to reduce board space requirement and lower overall system costs. The XR16L2551 also offers a pin select for Intel or Motorola data bus interface to reduce hardware design cycle.

The XR16L2550, XR16L2551 and XR16L2552 have 16-byte of TX and RX FIFOs for larger data buffering and provide automatic hardware (RTS/CTS) or software (Xon/Xoff) flow control to eliminate receiver data overflow and wasteful re-transmissions. In addition, the devices include the wireless infrared encoder/decoder for wireless communications. The XR16L2450 has one byte of TX and RX FIFO as its predecessor, the ST16C2450, but with lower operating voltage and 5V tolerant inputs. The 4 devices are pin and function compatible with their previous 5V series.

For UART technical support or to obtain an IBIS model for this product, please email Exar's UART Technical Support group.

Part NumberPkg CodeRoHSMin
StatusBuy NowOrder Samples
XR16L2551ILQFN32-4085OBSUpgrade: XR16L2551IL-F

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. 
CPU InterfaceIntel or Motorola
Max Data Rate @ 5/3.3/2.5/1.8V (Mbps)3.125/1.875/1/na
Tx/Rx FIFO (Bytes)16/16
Tx/Rx FIFO CtrsNo
Tx/Rx FIFO INT TrigNo/ 4 Levels
IrDa SupYes
5V Tol InputsYes
Sup V2.25-5.5
PkgsQFN-32, TQFP-48
Data Rate @ 5/3.3/2.5V3.1/1.8/1.0