XR19L212 Datasheet, PDF (1/52 Pages) Exar Corporation – TWO CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER

XR19L212
TWO CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
MAY 2007
REV. 1.0.0
GENERAL DESCRIPTION
The XR19L212 (L212) is a highly integrated device that
combines a full-featured two channel Universal
Asynchronous Receiver and Transmitter (UART) and RS-
232 transceivers. The L212 is designed to operate with a
single 3.3V or 5V power supply. The L212 is fully compliant
with EIA/TIA-232-F Standards from a +3.3V to +5.5V power
supply. The device operates at 1 Mbps 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 L212 operates in four different modes: Active, Partial
Sleep, Full Sleep and Power-Save. Each mode can be
invoked via hardware or software. Upon power-up, the
L212 is in the Active mode where the UART and RS-232
transceiver function normally. 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, both
the crystal oscillator and the charge pump are turned off.
While the UART is in the Sleep mode, the Power-Save
mode isolates the core logic from the control signals (chip
select, read/write strobes, address and data bus lines) to
minimize the power consumption. 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 +3.3V to +5.5V
operation
• Up to 1 Mbps 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 61000-4-2, Air-Gap Discharge
■ +/- 8kV - IEC 61000-4-2, 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#)
CSA# (CS#)
CSB#
INTA (IRQ#)
INTB
RESET (RESET#)
I/M#
RXBSEL
*5 V Tolerant
Inputs
Crystal
Osc/Buffer
BRG
64 Byte
TX & RX
FIFO
Modem
I/Os
TXA
RXA
RTSA#
CTSA#
Channel A
Channel B
UART
XR19L212
CTSB#
RTSB#
TXB
RXB
Charge Pump
5K
5K
VREF+
VREF-
TXDA
RXDA
RTSA
CTSA
Ch A Transceiver
Channel B
Transceiver
(See Figure 6)
RS-232 Transceiver
CTSB
RTSB
TXDB
TXB
RXDB
RXB
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com