Photocoupler for RS-232C 100kbps communication applications

Jon Lawson

Toshiba Electronics Europe has launched a new photocoupler suited to communication applications in factory automation equipment and home appliances. It is capable of supporting signal transfer speeds of up to 100 kbps and can be driven by a low input current of just 1mA.

This new IC features a high current transfer ratio (IC/IF) of 900 % (min) at an input current of 0.5 mA. As the guaranteed propagation delay is 25 us (max) at an input current of IF=1.6 mA, and 7 us (max) at IF=12 mA, this product is suitable for insulated communication interfaces such as RS-232C.

The widely used RS-232C communication interface and standard operates in the rate range between several kbps to 100 kbps. For this application general purpose transistor couplers are not satisfactory in terms of performance while 1 Mbps class IC couplers are often too expensive. The TLP2703 is the ideal solution, configured with a high output power infrared LED chip and a high speed photodarlington transistor.

The TLP2703 is housed in SO6L package with a max. height of 2,3mm. With a creepage distance of 8 mm and an isolation voltage of 5 kVrms the TLP2703 is suitable for use in applications requiring high insulation performance. Its guaranteed operating temperature range is up to +125°C, which allows the implementation in compact industrial equipment that contains a greater density of components and therefore higher internal temperatures.