LTC1344AIG#TRPBF

Overview

The LTC1344AIG#TRPBF is a software-selectable cable terminator manufactured by Analog Devices Inc. in a 24-lead SSOP package. It provides six multiprotocol cable terminators for serial interfaces, supporting RS232 (V.28), RS423 (V.10), RS422 (V.11), RS485, RS449, EIA530, V.35, and X.21 standards. The device operates with a positive supply voltage of 4.75V to 5.25V and a negative supply voltage of -5V ± 5%. It features a data bus latch feature allowing select line sharing between multiple interface ports. The component ensures outputs do not load the line when power is off and includes termination configurations such as RS422 100Ω differential loads and V.35 T-network loads.

Feature Summary

• Software-selectable cable termination for multiple serial protocols including RS232, RS422, and V.35
• Outputs remain high impedance to prevent line loading when power is removed
• Data bus latch feature enables sharing of control lines across multiple interface ports
• Configurable as differential loads or open circuits depending on transceiver requirements

Applications

• DTE or DCE multiprotocol serial interfaces with DB-25 connectors
• Channel Service Unit (CSU) and Data Service Unit (DSU) implementations
• Data routers requiring flexible serial communication standards

Procurement Notes

Verify the specific ordering suffix #TRPBF indicates tape and reel packaging upon procurement. Confirm that the 'IG' suffix corresponds to the industrial temperature range (-40°C to +85°C) as defined in the manufacturer's datasheet. Ensure compatibility with the required logic levels and supply voltages before finalizing purchase orders.

Selection Notes

Select the LTC1344A over the standard LTC1344 only if the specific Mode Selection table differences align with the design requirements. Ensure the application utilizes TTL level inputs for M0, M1, M2, and DCE/DTE pins. Verify that the system architecture can accommodate the shared select line configuration enabled by the LATCH pin functionality.

Part Context

The LTC1344A belongs to the Linear Technology multiprotocol serial interface family. It is designed to work in conjunction with transceivers like the LTC1543 and LTC1544 to form complete software-selectable serial ports. This component addresses the complexity of switching cable terminations for various electrical standards without mechanical relays.

Replacement Considerations

The LTC1344ACG#TRPBF serves as a commercial grade alternative with identical functionality but a different operating temperature range (0°C to 70°C). Verify thermal requirements before substitution.

FAQ

How does the LTC1344A handle line loading when power is off?

The device outputs are designed to remain in a high impedance state, ensuring they do not load the transmission line when the device is powered down.

What is the function of the LATCH pin?

The LATCH pin allows the select lines (M0, M1, M2, DCE/DTE) to be shared among multiple LTC1344A devices. When held low, inputs are transparent; when high, the input states are latched.

Which protocols are supported by the software-selectable terminators?

The LTC1344A supports RS232 (V.28), RS423 (V.10), RS422 (V.11), RS485, RS449, EIA530, EIA530-A, V.35, V.36, and X.21.