1/18March 2004
■ ESD PROTECTION FOR RS-232 I/O PINS:
±8KV IEC 1000-4-2 CONTACT DISCHARGE
±15KV HUMAN B ODY MODE L
■ 1µA SUPPLY CURRENT ACHIEVED WHEN
IN AUTO-POWERDOWN
■ 250Kbps M INIMUM GUARANTEED DATA
RATE
■ GUARANTEED 6V/µsSLEWRATERANGE
■ GUARANTEED MOUSE DRIVEABILITY
■ 0.1µF EXTERNAL CAPACITORS
■ MEET EIA/TIA-232 SPECIFICATIONS DOWN
TO 3V
■ AVAILABLE IN SO-28, SSOP-28, T SSOP28
AND FLIP-CHIP28 PACKAGES
DESCRIPTION
The ST3243E dev ice consists of 3 drivers, 5
receive rs and a dual charge-pump circuit. The
dev ice meets the requirements of EIA/TIA and
V.28/ V.24 communication standards providing
high data rate capability and enhanc ed
electrost at ic discharge (ES D ) protection. All
transmitter outputs and receiver input are
protected to ±8KV USING IEC 1000-4-2 contact
disch arge and ±15KV using the Human Body
Model. The receiver R2 is alway s active to
implement a wake-up feature for s erial port.
The ST3243E has a proprietary low-dropout
transmitter output st age enabling true R S-232
performanc e from a 3 .0V to 5.5V supply with a
dual c harge pump. T he device is g uarant eed to
run at data rat es of 250kbps while maintaining
RS-232 output levels.
The Auto-powerdown feature fu nctions when
FORCEON is low and FORCEOFF
is h igh. During
this mode of operation, if the dev ice does not
sen se a v alid R S-232 signa l, the driver outputs are
disabled. If FORCEOFF
is s et low, both drivers
and re ceiv ers (expert R2B) are shut off, and
sup ply current is reduced t o 1µA. Disconnecting
the serial port or turning of f the peripheral drives
cau se s the auto-powerdown condition to occur.
Auto-powerdown can be disabled when
FORCEON and FORCE OF F
are h igh, and shoul d
be done when driving a serial mouse. With
Auto-powerdown enabled, the d ev ice i s activated
automatically when a valid s ignal is a pplied to any
receiver input.
Typical application are in notebook, subnotebook ,
palm top computers, battery-powered equipment,
hand-held equipment, peripherals and printe rs.
ST3243E
±15KV ESD PROTECTED 3 TO 5.5V, 400KBPS,
RS-232 TRANSCEIVER WITH AUTO-POWERDOWN
SSOP
SOP
TSSOP
Flip-Chip28
