TTC-218

Overview

The Tamura TTC-218 is a through-hole audio transformer designed for telephone coupling applications. It features a 600 Ohm primary impedance and a 600 Ohm secondary impedance, providing a 1:1 turns ratio. The device operates within a frequency range of 660Hz to 3.5kHz. Key electrical specifications include a DC resistance (DCR) of 49 Ohms and a maximum current rating of 50mA DC. The component is housed in a DIP package with a height of 8.8mm.

Feature Summary

• Provides galvanic isolation for telephone line coupling
• Maintains signal integrity across standard voice frequencies
• Supports direct current bias up to 50mA

Applications

• Telephone exchange equipment
• Voice communication systems
• Analog audio interface circuits

Procurement Notes

Verify the specific suffix designation when ordering, as variants such as TTC-218-2 exist with identical core specifications but may differ in packaging or manufacturing lot details. Confirm that the required DIP footprint matches the 8.8mm height constraint. Ensure the application current does not exceed the 50mA DC limit to prevent saturation or thermal issues. Cross-reference the datasheet version to ensure compatibility with the target circuit design requirements.

Selection Notes

Select this component for applications requiring precise 600 Ohm impedance matching in analog voice channels. The wide frequency response supports standard telephony bandwidths effectively. Consider the through-hole mounting style for robust mechanical stability in industrial environments. Evaluate the 49 Ohm DCR against source impedance requirements to minimize insertion loss. This transformer is suitable for low-power signal transmission where high isolation is necessary.

Part Context

The TTC-218 belongs to Tamura's series of specialized audio transformers engineered for telecommunications. These components are critical for maintaining signal fidelity in legacy and modern voice networks. The product line emphasizes reliability and consistent performance in coupled line applications. Tamura designs these units to meet stringent industry standards for acoustic and electrical performance in telephone infrastructure.

Replacement Considerations

The TTC-218-2 is a confirmed substitute part number with equivalent electrical characteristics. Verify pinout compatibility before swapping. No other generic replacements are documented.