TLP185GB

The TLP185GB is a high-CTR photocoupler from Toshiba with a GaAs infrared LED optically coupled to a phototransistor in a compact SOP4 package. The GB rank provides a current transfer ratio of 100-200% at IF=5 mA, making it the highest gain variant in the TLP185 family. This high CTR enables reliable switching with very low LED drive currents, reducing power consumption in battery-powered and energy-sensitive applications. The device maintains the same 3750 Vrms isolation voltage and safety approvals as the standard TLP185.

The TLP185GB operates identically to the standard TLP185 but with tighter CTR binning in the GB rank (100-200%). The infrared LED converts electrical current to light, which crosses the internal isolation barrier and generates base current in the phototransistor. The phototransistor amplifies this base current by its hFE to produce collector current. The high CTR of the GB rank means that for a 5 mA LED current, the collector current will be between 5 mA and 10 mA, enabling direct interfacing to low-power logic circuits without additional amplification stages.

• High-gain signal isolation in battery-powered devices
• Switch-mode power supply opto-isolated feedback
• Low LED drive current optical switching
• Industrial PLC I/O module signal isolation
• Medical device patient isolation barriers