描述 Description

The TRS3222 consists of two line drivers, two line receivers, 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. The device operates at data signaling rates up to 250 kbit/s and a maximum of 30-V/μ s driver output slew rate. The TRS3222 can be placed in the power-down mode by setting PWRDOWN low, which draws only 1 μ A from the power supply. When the device is powered down, the receivers remain active while the drivers are placed in the high-impedance state. Also, during power down, the onboard charge pump is disabled; V+ is lowered to VCC, and V- is raised toward GND. Receiver outputs also can be placed in the high-impedance state by settingEN high.

特性 Features

? 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 kbit/s
? Two Drivers and Two Receivers
? Low Standby Current . . . 1 μ A Typical
? External Capacitors . . . 4 × 0.1 μ F
? Accepts 5-V Logic Input With 3.3-V Supply
? Alternative High-Speed Pin-Compatible Device (1 Mbit/s)
? TRSF3222

? APPLICATIONS
? Battery-Powered Systems
? PDAs
? Notebooks
? Laptops
? Palmtop PCs
? Hand-Held Equipment