描述 Description

The TRS3237E consists of five line drivers, three 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. This device operates at data signaling rates of 250 kbit/s in normal operating mode (MBAUD?=?GND) and 1Mbit/s when MBAUD = VCC. The driver output slew rate is a maximum of 30 V/μs. The TRS3237E transmitters are disabled and the outputs are forced into high-impedance state when the device is in shutdown mode (SHDN = GND) and the supply current falls to less than 1 μA. Also, during shutdown, 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 setting enable (EN) high. ROUT1B remains active all the time, regardless of the EN and SHDN condition. The TRS3237EC is characterized for operation from 0°C to 70°C. The TRS3237EI is characterized for operation from –40°C to 85°C.

特性 Features

? 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 From 250 kbits/s to 1 Mbit/s
? Low Standby Current . . . 1 μA Typical
? External Capacitors . . . 4 × 0.1 μF
? Accepts 5-V Logic Input With 3.3-V Supply
? Designed to Be Interchangeable With Industry Standard ’3237E Devices
? Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
? ESD Protection for RS-232 I/O Pins
? ±15 kV – Human-Body Model (HBM)
? ±8 kV – IEC61000-4-2, Contact Discharge
? ±15 kV – IEC61000-4-2, Air-Gap Discharge

? APPLICATIONS
? Battery-Powered, Hand-Held, and Portable Equipment
? PDAs and Palmtop PCs
? Notebooks, Sub-Notebooks, and Laptops
? Digital Cameras
? Mobile Phones and Wireless Devices