The TRS3221E is a single driver, single receiver
RS-232 solution operating from a single VCC supply. The RS-232 pins
provide IEC G1000-4-2 ESD protection. The device meets the requirements of
TIA/EIA-232-F and provides the electrical interface between an asynchronous
communication controller and the serial-port connector. The charge pump and four
small external capacitors allow operation from a single 3V to 5.5V supply. These
devices operate at data signaling rates up to 250kbit/s and a maximum of 30V/µs
driver output slew rate.
Flexible control
options for power management are available when the serial port is inactive. 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 on the receiver input, the driver output
is disabled. If FORCEOFF is set low and EN
is high, both the driver and receiver are shut off, and the supply current is
reduced to 1 µA. Disconnecting the serial port or turning off the peripheral drivers
causes the auto-powerdown condition to occur. Auto-powerdown can be disabled when
FORCEON and FORCEOFF are high.
With auto-powerdown enabled, the device is
activated automatically when a valid signal is applied to the receiver input. The
INVALID output notifies the user if an RS-232 signal is
present at the receiver input. INVALID is high (valid data) if
the receiver input voltage is greater than 2.7V or less than –2.7V, or has been
between –0.3V and 0.3V for less than 30µs. INVALID is low
(invalid data) if the receiver input voltage is between –0.3V and 0.3V for more than
30µs. Refer to Figure 6-5 for receiver input levels.
The TRS3221E is a single driver, single receiver
RS-232 solution operating from a single VCC supply. The RS-232 pins
provide IEC G1000-4-2 ESD protection. The device meets the requirements of
TIA/EIA-232-F and provides the electrical interface between an asynchronous
communication controller and the serial-port connector. The charge pump and four
small external capacitors allow operation from a single 3V to 5.5V supply. These
devices operate at data signaling rates up to 250kbit/s and a maximum of 30V/µs
driver output slew rate.
Flexible control
options for power management are available when the serial port is inactive. 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 on the receiver input, the driver output
is disabled. If FORCEOFF is set low and EN
is high, both the driver and receiver are shut off, and the supply current is
reduced to 1 µA. Disconnecting the serial port or turning off the peripheral drivers
causes the auto-powerdown condition to occur. Auto-powerdown can be disabled when
FORCEON and FORCEOFF are high.
With auto-powerdown enabled, the device is
activated automatically when a valid signal is applied to the receiver input. The
INVALID output notifies the user if an RS-232 signal is
present at the receiver input. INVALID is high (valid data) if
the receiver input voltage is greater than 2.7V or less than –2.7V, or has been
between –0.3V and 0.3V for less than 30µs. INVALID is low
(invalid data) if the receiver input voltage is between –0.3V and 0.3V for more than
30µs. Refer to Figure 6-5 for receiver input levels.