UART with Higher Operating Speed and Lower Access Time


The ST16C450 is a universal asynchronous receiver and transmitter. The ST16C450 is an improved version of the NS16450 UART with higher operating speed and lower access time. A programmable baud rate generator is provided to select transmit and receive clock rates from 50 bps to 1.5 Mbps.

The ST16C450 on board status registers provides the error conditions, type and status of the transfer operation being performed. Included is complete MODEM control capability, and a processor interrupt system that may be software tailored to the user’s requirements. The ST16C450 provides internal loop- back capability for on board diagnostic testing.

The ST16C450 is available in 40 pin PDIP, 44 pin PLCC, and 48 pin TQFP packages. It is fabricated in an advanced CMOS process to achieve low drain power and high speed requirements.

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

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  • Pin to pin and functionally compatible to the Industry Standard 16450
  • 1.5 Mbps transmit/receive operation (24MHz)
  • Programmable word lengths (5, 6, 7, 8)
  • Even, odd, force, or no parity generation and detection
  • Independent transmit and receive control
  • Standard modem interface
  • Low operating current ( 1.2mA typ.)
  • Pb-Free, RoHS Compliant Versions Offered


  • Battery Operated Electronics
  • Internet Appliances
  • Handheld Terminal
  • Personal Digital Assistants
  • Cellular Phones DataPort

Design Tools

Evaluation Hardware and Software


Pkg Code Details Quantities Dimensions PDF
  • JEDEC Reference: MS-011
  • MSL Pb-Free: n/a
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 50.0ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: n/a
  • Quantity per Tube: 9
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): n/a
  • Tape & Reel Unit Orientation: n/a
  • Dimensions: inch
  • Length: 2.100 max.
  • Width: 0.580 max.
  • Thickness: 0.195 max.
  • Lead Pitch: 0.100
  • JEDEC Reference: MS-018
  • MSL Pb-Free: L1 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 38.0ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 500
  • Quantity per Tube: 27
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 330 x 32 x 24
  • Tape & Reel Unit Orientation: Pin 1 at sprocket hole.
  • Dimensions: inch
  • Length: 0.653
  • Width: 0.653
  • Thickness: 0.152
  • Lead Pitch: 1.27
  • JEDEC Reference: MO-026
  • MSL Pb-Free: L3 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 59.0ºC/W
  • Bulk Pack Style: Tray
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 1500
  • Quantity per Tube: n/a
  • Quantity per Tray: 250
  • Reel Size (Dia. x Width x Pitch): 330 x 16 x 12
  • Tape & Reel Unit Orientation: Pin 1 at sprocket hole.
  • Dimensions: mm
  • Length: 7.0
  • Width: 7.0
  • Thickness: 1.0
  • Lead Pitch: 0.5

Parts & Purchasing

Part Number Pkg Code RoHS Min Temp Max Temp Status Buy Now Order Samples
ST16C450CJ44-F PLCC44 0 70 EOL Suggested:
ST16C450CJ44TR-F PLCC44 0 70 EOL
ST16C450CP40 PDIP40 0 70 OBS Suggested:
ST16C450CP40-F PDIP40 0 70 OBS Suggested:
ST16C450CQ48-F TQFP48 0 70 EOL Suggested:
ST16C450CQ48TR-F TQFP48 -40 85 EOL Suggested:
ST16C450IJ44-F PLCC44 -40 85 EOL Suggested:
ST16C450IJ44TR-F PLCC44 -40 85 EOL Suggested:
ST16C450IP40 PDIP40 -40 85 OBS Suggested:
ST16C450IP40-F PDIP40 -40 85 OBS Suggested:
ST16C450IQ48-F TQFP48 -40 85 EOL Suggested:
ST16C450IQ48TR-F TQFP48 -40 85 EOL
Show obsolete parts
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.
Distribution Date Description File
07/12/2017 Product Discontinuation Notice PDN_17-0626-01-1033.pdf
07/11/2017 Product Discontinuation Notification PDN_17-0623-01-1033.pdf
08/17/2016 Qualification of ANST as an alternate manufacturing site. PCN 16-0417-02 ANST-1033.pdf
11/05/2015 Updated information subsequent to original published PCN 13-0834-03 on 04/02/2014. ASE Malaysia as alternate assembly site Addition of qualified alternate assembly site of 28, 44, 68L PLCC packaged products. PCN 13-0834-03A PLCC 28-44-1033.pdf
07/18/2014 Elimination of back mark. Eliminate back mark; consolidate information in top mark. PCN_14-0313-01-1033.pdf
04/02/2014 Qualification of ASE Malaysia for assembly of 28, 44, 68L PLCC packaged products. Alternate assembly site. PCN_13-0834-03-1033.pdf
10/03/2013 Product Discontinuation Notification Discontinued. PDN_13-1003-01-1033.pdf
10/03/2013 Addition of an alternate qualified assembly site, ASE Chung-Li (Taiwan). Material change and alternate assembly site. PCN_13-0623-03-1033.pdf
10/17/2012 Exar has qualified Millennium Microtech/Thailand as an alternate assembly supplier for 28, 44 and 68 lead PLCC packages in addition to the existing supplier, Unisem/Indonesia. Capacity enhancement PCN_12-0824-01-1033.pdf
04/11/2011 Product Discontinuation Notice In support of “green” initiatives, the listed leaded part numbers will be discontinued by Exar. PDN_11-0411-01-1033.pdf