**LTC1387CG#TRPBF: A Comprehensive Overview of Linear Technology's 5V RS-232 Multiplexer/Driver**

The **LTC1387CG#TRPBF** from Linear Technology (now part of Analog Devices) represents a highly integrated solution for **managing multiple RS-232 data streams** in space-constrained and power-sensitive applications. This device combines a **dual RS-232 driver/receiver pair** with a **2-channel multiplexer**, all operating from a single **5V power supply**, making it a uniquely efficient component for modern data communication systems.

A primary strength of the LTC1387 is its ability to **multiplex two complete RS-232 ports** onto a single DB-9 or similar connector. This functionality is invaluable for systems where a single serial connection must serve two different devices or a primary and a backup channel. The integrated multiplexer switches both the driver outputs and receiver inputs, controlled by a single TTL/CMOS-compatible select pin (**SEL**), which **simplifies digital interfacing** and reduces the need for external logic components.

Despite its complex functionality, the device is renowned for its **low power consumption**. It incorporates a proprietary **charge-pump circuitry** that generates the necessary ±10V RS-232 voltage levels from the single 5V supply without requiring expensive external bipolar power supplies. This design not only simplifies the board layout but also enhances overall system reliability. Furthermore, the device features a **software shutdown mode** (controlled by the **SHDN** pin), which reduces the supply current to a mere 10µA, making it ideal for battery-powered and portable equipment.

The drivers are **fully compliant with all EIA-232-E specifications**, ensuring robust data transmission over typical distances. The receivers, featuring **schmitt-trigger inputs**, provide excellent noise immunity, allowing them to accurately interpret signals even in electrically noisy environments. The **LTC1387CG** is offered in a compact 20-pin SSOP (CG) package, with the #TRPBF suffix indicating a tape-and-reel packaging for high-volume automated assembly.

**ICGOODFIND:** The LTC1387CG#TRPBF is an exceptional integrated circuit that masterfully combines a dual transceiver and a 2:1 multiplexer. Its operation from a single 5V supply, coupled with ultra-low power shutdown mode and robust RS-232 performance, establishes it as a superior choice for **multichannel serial data switching** in demanding applications.

**Keywords:** RS-232 Multiplexer, Single 5V Supply, Low Power Shutdown, Charge-Pump Circuitry, Schmitt-Trigger Inputs.