LTC1387IG#TRPBF

Drivers, Receivers, Transceivers Overview

The LTC1387IG#TRPBF is a single-supply, low-power CMOS bidirectional transceiver manufactured by Analog Devices Inc. It supports reconfigurable RS-232 and RS-485/RS-422 protocols within a 20-lead SSOP package. The device operates from a single 5V supply (4.75V to 5.25V) with an onboard charge pump generating boosted positive and negative supplies using four external 0.1µF capacitors. It features two RS-232 drivers/receivers or one RS-485 driver/receiver. Key electrical parameters include a typical supply current of 7mA, reducing to 5mA in shutdown mode. The RS-485 driver supports data rates up to 5MBd in fast slew mode and 150kBd in slow slew mode. Receiver inputs withstand -25V, and the industrial temperature range (-40°C to +85°C) applies to the 'I' suffix variant.

Drivers, Receivers, Transceivers Feature Summary

• Reconfigurable multiprotocol interface supporting both RS-232 and RS-485/RS-422 standards via software-selectable logic inputs.
• Integrated onboard charge pump generates necessary voltage swings for RS-232 compliance using only a single 5V supply.
• Logic-selectable fast and slow slew rates for the RS-485 driver to optimize bandwidth or minimize signal reflections.
• Dedicated loopback mode allows internal connection of driver outputs to receiver inputs for diagnostic self-testing.

Drivers, Receivers, Transceivers Applications

• Point-of-sale terminals requiring flexible interface configurations.
• Cable repeaters needing robust signal transmission capabilities.
• Level translators converting between different serial communication standards.
• Software-selectable multiprotocol interface ports in embedded systems.

Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm package type and temperature grade. The '#TRPBF' suffix indicates tape-and-reel packaging and lead-free status. Confirm that the component meets RoHS3 specifications as stated in the datasheet. Ensure the intended application environment falls within the specified operating temperature range for the 'I' grade part. Cross-reference the manufacturer part number with authorized distributors to ensure authenticity.

Drivers, Receivers, Transceivers Selection Notes

Select this component when a single IC must support multiple serial communication standards without external level shifters. The choice between RS-232 and RS-485 modes is determined by the state of the 485/232 pin. Consider the power consumption requirements, as the shutdown mode reduces current significantly. Evaluate the need for high input impedance receivers and fault protection features like thermal shutdown. Ensure sufficient board space for the required four 0.1µF capacitors for the charge pump circuit.

Drivers, Receivers, Transceivers Part Context

The LTC1387 belongs to Analog Devices' family of low-power RS-232 and RS-485 interface transceivers. It is designed to replace discrete solutions by integrating protocol conversion and voltage generation into a single chip. The 'IG' designation specifies the industrial temperature range and SSOP package, while the '#TRPBF' denotes the reel packaging format. This part serves as a versatile solution for systems requiring adaptable serial communication interfaces.

Drivers, Receivers, Transceivers Replacement Considerations

ISL81387IAZ by Renesas Electronics Corporation is a documented similar replacement part. Verify pin compatibility and electrical parameter alignment before substitution. Check if the alternative part offers equivalent ESD protection levels and package dimensions. Ensure the replacement supports the same voltage ranges and control logic functions.

Drivers, Receivers, Transceivers FAQ

How does the LTC1387 generate RS-232 voltage levels?

It uses an onboard charge pump that requires four external 0.1µF capacitors to generate boosted positive and negative supplies from a single 5V source.

What is the function of the SLEW pin in RS-485 mode?

The SLEW pin controls the driver slew rate. A high logic level enables fast slew rate for higher data rates, while a low logic level enables slow slew rate to reduce reflections on improperly terminated cables.

Can the receiver inputs handle voltages outside the supply rails?

Yes, the receiver inputs can withstand up to -25V without damage, providing robust protection against transient voltages.