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SEPTEMBER 2003
ST16C2450
2.97V TO 5.5V DUART
REV. 4.0.0
GENERAL DESCRIPTION
The ST16C2450 (2450) is a dual universal asynchro-
nous receiver and transmitter (UART). The
ST16C2450 is an improved version of the
ST16C2450 with lower operating voltage and 5 volt
tolerant inputs. The 2450 provides enhanced UART
functions, a modem control interface and data rates
up to 1.5 Mbps. Onboard status registers provide the
user with error indications and operational status. In-
dependent programmable baud rate generators are
provided to select transmit and receive clock rates up
to 1.5 Mbps. An internal loopback capability allows
onboard diagnostics. The 2450 is available in a 44-
pin PLCC and 48-pin TQFP packages. The 2450 is
fabricated in an advanced CMOS process capable of
operating from 2.97 volt to 5.5 volt power supply. The
devices with a top marking of "A2 YYWW" or newer
have 5 volt tolerant inputs.
FEATURES
Added feature in devices with top marking "A2
YYWW" and newer:
s
5 Volt Tolerant Inputs
•
2.97 to 5.5 Volt Operation
•
Pin-to-pin compatible to Exar’s ST16C2450,
ST16C2550,
XR16C2850
TQFP package
XR16L2550,
XR16L2750
and
•
Pin-to-pin compatible to TI’s TL16C752B on the 48-
•
2 independent UART channels
s
Up to 1.5 Mbps data rate with a 24 MHz crystal
oscillator or external clock frequency
1 byte Transmit FIFO
1 byte Receive FIFO with error tags
Status report registers
Modem control signals (CTS#, RTS#, DSR#,
DTR#, RI#, CD#)
Programmable character lengths (5, 6, 7, 8)
with even, odd, or no parity
s
s
s
s
APPLICATIONS
•
Portable Appliances
•
Telecommunication Network Routers
•
Ethernet Network Routers
•
Cellular Data Devices
•
Factory Automation and Process Controls
s
•
Crystal oscillator or external clock input
•
TTL compatible inputs, outputs
•
Industrial temperature ranges
•
48-TQFP and 44-PLCC packages
F
IGURE
1. ST16C2450 B
LOCK
D
IAGRAM
A2:A0
D7:D0
IOR#
IOW#
CSA#
CSB#
INTA
INTB
UART Channel A
UART
Regs
8-bit Data
Bus
Interface
BRG
16 Byte TX FIFO
TX & RX
16 Byte RX FIFO
2.25 to 5.5 Volt VCC
GND
TXA, RXA, DTRA#,
DSRA#, RTSA#,
DTSA#, CDA#, RIA#,
OP2A#
UART Channel B
(same as Channel A)
Reset
TXB, RXB, DTRB#,
DSRB#, RTSB#,
CTSB#, CDB#, RIB#,
OP2B#
XTAL1
XTAL2
Crystal Osc/Buffer
Exar
Corporation 48720 Kato Road, Fremont CA, 94538
•
(510) 668-7000
•
FAX (510) 668-7017
•
www.exar.com
EXAR [ EXAR CORPORATION ]
