TLP121(BL,F)

Overview

The TLP121(BL,F) is a single-channel transistor output optocoupler manufactured by Toshiba Semiconductor and Storage. It integrates a gallium arsenide infrared emitting diode with a phototransistor in a mini flat DIP-4 plastic package. The device provides electrical isolation between input and output circuits. Key electrical parameters include a minimum collector-emitter breakdown voltage of 80 V, a maximum forward current of 50 mA, and a maximum insulation voltage of 3750 Vrms. The nominal current transfer ratio is specified at 100% for the BL rank. The component operates within a temperature range of -25 °C to 85 °C.

Feature Summary

• Integrates a GaAs infrared LED and a phototransistor for signal transmission
• Provides high-voltage electrical isolation via an internal insulating barrier
• Designed for surface mount assembly in a compact mini flat package

Applications

• Office machines such as copiers and printers
• Programmable controllers and industrial automation systems
• AC/DC input modules for data acquisition
• Telecommunication equipment interfaces

Procurement Notes

Verify the specific suffix (BL,F) against the manufacturer's official datasheet to confirm the current transfer ratio ranking and lead-free status. Ensure the procurement source provides valid UL recognition documentation if required for end-product safety compliance. Confirm that the tin/lead terminal finish meets the application requirements, as this variant may not be RoHS compliant.

Selection Notes

Select this component when a small form factor is required for surface mount applications involving low-speed digital signal isolation. The 80 V collector-emitter voltage rating suits general-purpose switching tasks. Verify that the 100% CTR rank aligns with the drive circuit design requirements. Consider thermal management constraints given the plastic package limitations in high-density layouts.

Part Context

This part belongs to the TLP121 series of mini flat couplers from Toshiba. The series is characterized by its small outline dimensions suitable for automated surface mount processing. Variants within the series differ primarily in current transfer ratio rankings and packaging suffixes. The TLP121 family is widely utilized in space-constrained electronic designs requiring reliable galvanic isolation.

Replacement Considerations

Direct substitutes must match the DIP-4 mini flat package, 80 V minimum collector-emitter voltage, and similar current transfer characteristics. Verify pinout compatibility and isolation voltage ratings before substitution. Cross-reference with other manufacturers' transistor output optocouplers offering equivalent isolation barriers and package footprints.