ST3243B_07 Datasheet, PDF (1/22 Pages) STMicroelectronics – 3 to 5.5 V, 400 Kbps, RS-232 transceiver with auto-power-down

ST3243B
ST3243C
3 to 5.5 V, 400 Kbps, RS-232 transceiver
with auto-power-down
Features
■ 1 µA supply current achieved when in auto-
power-down
■ 250 kbps minimum guaranteed data rate
■ Guaranteed 6 V/µs slew rate range
■ Guaranteed mouse drive ability
■ 0.1 µF external capacitors
■ Meet EIA/TIA-232 specifications down to 3 V
■ Available in 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 3.0 V to 5.5 V supply with a
dual charge pump. The device is guaranteed to
run at data rates of 250 kbps while maintaining
RS-232 output levels.
The Auto-power-down 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 1 mA.
Disconnecting the serial port or turning off the
SSOP
TSSOP
peripheral drives causes the auto-power-down
condition to occur.
Auto-power-down can be disabled when
FORCEON and FORCEOFF are high, and should
be done when driving a serial mouse. With Auto-
power-down enabled, the device is activated
automatically when a valid signal is applied to any
receiver input.
Typical application are in notebook, sub-
notebook, palmtop computers, battery-powered
equipment, hand-held equipment, peripherals and
printers.
Table 1. Device summary
Order code Temperature range
ST3243CPR
0 to 70 °C
ST3243BTR
-40 to 85 °C
Package
SSOP-28 (tape and reel)
TSSOP28 (tape and reel)
Packaging
1350 parts per reel
2500 parts per reel
November 2007
Rev 8
1/22
www.st.com
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