Lite-On LTV-817 series - CTR and Part Markings

Current transfer ratio (CTR) is a parameter of photocouplers, which is expressed as a percentage indicating the ratio of the output current (Ic) to the input current (If). Ensuring your circuit has sufficient CTR needs to be considered when designing, otherwise the photocoupler’s output may be too small and cause malfunctions.

You can look up the CTR rank in the datasheet, and clarify the part number details or top marking for your specific photocoupler. LTV-817 from Lite-On Inc is an example.

Different ranks of CTR:
image

The breakdown of part number:

The default CTR RANK option code is none if no request for a specific CTR rank is made. Then you will receive either one of CTR. If you need a specific CTR rank, you should include that request in the “Order Notes” section of your Digi-Key order, or inform your Customer Support representative of this requirement when placing an order.

You can look at the rank code on the top marking to confirm CTR of physical parts.

image

Related topic:
Current Transfer Ratio - CTR