ST3243
3 to 5.5V, 400Kbps, RS-232 Transceiver
with auto-powerdown
General features
s
1碌A(chǔ) supply current achieved when in auto-
powerdown
250kbps minimum guaranteed data rate
Guaranteed 6V/碌s slew rate range
Guaranteed mouse drive ability
0.1碌F external capacitors
Meet EIA/TIA-232 specifications down to 3V
Available in SO-28, SSOP-28 and TSSOP28
SSOP
TSSOP
SOP
s
s
s
s
s
s
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 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.
Order code
Part number
ST3243CDR
ST3243CPR
ST3243CTR
ST3243BTR
Temperature range
0 to 70 擄C
0 to 70 擄C
0 to 70 擄C
-40 to 85 擄C
Package
SO-28 (Tape & Reel)
SSOP-28 (Tape & Reel)
TSSOP28 (Tape & Reel)
TSSOP28 (Tape & Reel)
Comments
1000 parts per reel
1350 parts per reel
2500 parts per reel
2500 parts per reel
March 2006
Rev 7
1/20
www.st.com
20