XR19L220_07 Datasheet, PDF (1/43 Pages) Exar Corporation – SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER

XR19L220
SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
MAY 2007
REV. 1.0.1
GENERAL DESCRIPTION
The XR19L220 (L220) is a highly integrated device that
combines a full-featured single channel Universal
Asynchronous Receiver and Transmitter (UART) and an
RS-232 transceiver. The L220 is designed to operate with a
single 3.3V or 5V power supply. The L220 is fully compliant
with EIA/TIA-232-F Standards from a +3.0V to +5.5V power
supply. The device operates at 250 Kbps data rate with
worst case 3K ohms load. Both RS-232 driver outputs and
receiver inputs can operate in harsh electrical environments
of +/-15V without damage and can survive multiple +/-15kV
ESD on the RS-232 lines, while maintaining RS-232 output
levels.
The L220 operates in four different modes: Active, Partial
Sleep, Full Sleep and Power-Save. Each mode can be
invoked via hardware or software. In the Active mode, all
functions are active. In the Partial Sleep mode, the internal
crystal oscillator of the UART or charge pump of the RS-
232 transceiver is turned off. In Full Sleep mode, the
internal crystal oscillator and the charge pump is turned off.
In the Power-Save mode, the core logic is isolated from the
control signals (chip select, read/write strobes, address and
data bus lines) to further reduce the power consumption. All
the RS-232 receivers remain active in any of these four
modes.
APPLICATIONS
• Battery-Powered Equipment
• Handheld and Mobile Devices
• Handheld Terminals
• Industrial Peripheral Interfaces
• Point-of-Sale (POS) Systems
FEATURES
• Meets true EIA/TIA-232-F Standards from +3.0V to +5.5V
operation
• Up to 250 Kbps data transmission rate
• 45us sleep mode exit (charge pump to full power)
• ESD protection for RS-232 I/O pins at
■ +/-15kV - Human Body Model
■ +/-15kV - IEC 1000-4-2, Air-Gap Discharge
■ +/- 8kV - IEC 1000-4-2, Contact Discharge
• Software compatible with industry standard 16550 UART
• Intel/Motorola bus select
• Complete modem interface
• Sleep and Power-save modes to conserve battery power
• Wake-up interrupt upon exiting low power modes
FIGURE 1. BLOCK DIAGRAM
PwrSave
A2:A0
D7:D0
IOR#
IOW# (R/W#)
CS#
INT (IRQ#)
RESET (RESET#)
I/M#
*5 V
Tolerant
Inputs
Crystal
Osc/Buffer
BRG
16 Byte
TX FIFO
16 Byte
RX FIFO
Modem
I/Os
TX
RX
RTS#
DTR#
CTS#
DSR#
RI#
CD#
UART
XR19L220
Charge Pump
5K
5K
5K
5K
5K
RS-232 Transceiver
VREF+
VREF-
TXD
RXD
RTS
DTR
CTS
DSR
RI
CD
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com