The MAX3221 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 a single 3-V to 5.5-V supply. These devices operate at data signaling rates up to 250 kbps and a maximum of 30-V/±s 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 validRS-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.
RS-232 Bus-Pin ESD Protection Exceeds ±15 kV Using Human Body Model (HBM)
Meets or Exceeds the Requirements of TIA/EIA-232-F and ITU V.28 Standards
Operates With 3-V to 5.5-V VCC Supply
Operates up to 250 kbps
One Driver and One Receiver
Low Standby Current: 1 µA Typical
External Capacitors: 4 × 0.1 µF
Accepts 5-V Logic Input With 3.3-V Supply
Alternative High-Speed Pin-Compatible Device (1 Mbps)
Automatic Power-Down Feature Automatically Disables Drivers for Power Savings