TCDT1120

Overview

The TCDT1120 is a single-channel transistor output optocoupler manufactured by Vishay Semiconductor Opto Division. It integrates a gallium arsenide infrared emitting diode with an NPN phototransistor in a 6-lead plastic dual inline package (DIP-6). Key electrical parameters include a maximum collector-emitter voltage of 70 V, a maximum collector current of 50 mA, and an insulation voltage of 5000 Vrms. The device features a minimum current transfer ratio of 40% at a forward current of 60 mA, with a typical forward voltage of 1.6 V. Switching characteristics include a rise time of 3 µs and a fall time of 3.7 µs.

Feature Summary

• Optical isolation between input and output circuits using a gallium arsenide infrared LED and NPN phototransistor.
• High insulation voltage capability of 5000 Vrms for safe signal transmission across potential barriers.
• Through-hole mounting in a standard 6-DIP package for reliable PCB integration.

Applications

• Switch-mode power supplies
• Line receiver circuits
• Computer peripheral interface systems

Procurement Notes

Verify the manufacturer part number against official Vishay documentation to ensure authenticity. Confirm that the specific order suffix matches the required package variant, as suffixes may indicate tape-and-reel or bulk packaging options rather than functional changes. Check lead times with authorized distributors, as standard lead times can vary significantly based on production schedules and regional availability.

Selection Notes

Select this component when high-voltage isolation is required for low-speed digital signal transmission. The 70 V collector-emitter voltage rating suits applications involving moderate voltage levels on the output side. Ensure the system design accommodates the specified 60 mA forward current limit for the input LED and verify that the 50 mA collector current capacity meets the load requirements of the receiving circuit.

Part Context

This component belongs to the TCDT112x series of transistor output optocouplers from Vishay. These devices are designed for general-purpose isolation tasks where cost-effective, through-hole solutions are preferred. The series offers standardized pinouts and electrical characteristics suitable for replacing older discrete isolation components in established industrial and consumer electronic designs.

Replacement Considerations

Direct replacements must match the 6-DIP package, 5000 Vrms isolation, and similar electrical ratings. Verify compatibility with existing board space and thermal constraints. Cross-reference with other Vishay TCDT models or equivalent industry-standard transistor output optocouplers ensuring identical pinout and voltage/current specifications.