The TRS3221 device consists of one line driver, one line receiver with dedicated enable
pin, and a dual charge-pump circuit with ±15-kV ESD protection pin-to-pin (serial-port connection
pins, including GND). 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 one
3-V to 5.5-V supply. The TRS3221 device operates at data signaling rates up to 250 kbps and a
maximum of 30-V/µs driver output slew rate.
Flexible control options for power management are available when the serial port is
inactive. The automatic 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 on the receiver input, the driver output is disabled and the supply
current is reduced to 1 µA. The INVALID output notifies the user if an
RS-232 signal is present at the receiver input.
The TRS3221 device consists of one line driver, one line receiver with dedicated enable
pin, and a dual charge-pump circuit with ±15-kV ESD protection pin-to-pin (serial-port connection
pins, including GND). 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 one
3-V to 5.5-V supply. The TRS3221 device operates at data signaling rates up to 250 kbps and a
maximum of 30-V/µs driver output slew rate.
Flexible control options for power management are available when the serial port is
inactive. The automatic 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 on the receiver input, the driver output is disabled and the supply
current is reduced to 1 µA. The INVALID output notifies the user if an
RS-232 signal is present at the receiver input.