ST3243_04 Datasheet, PDF (1/14 Pages) STMicroelectronics – 3 TO 5.5V, 400KBPS, RS-232 TRANSCEIVER WITH AUTO-POWERDOWN

ST3243
3 TO 5.5V, 400KBPS, RS-232
TRANSCEIVER WITH AUTO-POWERDOWN
s 1µA SUPPLY CURRENT ACHIEVED WHEN
IN AUTO-POWERDOWN
s 250Kbps MINIMUM GUARANTEED DATA
RATE
s GUARANTEED 6V/µs SLEW RATE RANGE
s GUARANTEED MOUSE DRIVEABILITY
s 0.1µF EXTERNAL CAPACITORS
s MEET EIA/TIA-232 SPECIFICATIONS DOWN
TO 3V
s AVAILABLE IN SO-28, SSOP-28 AND
TSSOP28
DESCRIPTION
The ST3243 device consists of 3 drivers, 5
receivers and a dual charge-pump circuit. The
device meets the requirements of EIA/TIA and
V.28/V.24 communication standards providing
high data rate capability.
The receiver R2 is always active to implement a
wake-up feature for serial port.
The ST3243 has a proprietary low-dropout
transmitter output stage enabling true RS-232
performance from a 3.0V to 5.5V supply with a
dual charge pump. The device is guaranteed to
run at data rates of 250kbps while maintaining
RS-232 output levels.
The Auto-powerdown feature functions when
FORCEON is low and FORCEOFF is high. During
this mode of operation, if the device does not
sense a valid RS-232 signal, the driver outputs are
disabled. If FORCEOFF is set low, both drivers
and receivers (expert R2B) are shut off, and
supply current is reduced to 1mA. Disconnecting
SOP
SSOP
TSSOP
the serial port or turning off the peripheral drives
causes the auto-powerdown condition to occur.
Auto-powerdown can be disabled when
FORCEON and FORCEOFF are high, and should
be done when driving a serial mouse. With
Auto-powerdown enabled, the device is activated
automatically when a valid signal is applied to any
receiver input.
Typical application are in notebook, subnotebook,
palmtop computers, battery-powered equipment,
hand-held equipment, peripherals and printers.
January 2004
1/14