Based on recommendations in the A1458 optocoupler datasheet and industry best practices:
When a new optocoupler part number like A1458 crosses your desk, the datasheet is the only source of truth. Unlike standard jellybean parts (e.g., 4N25), an "A1458" suggests either a proprietary manufacturer code, a high-reliability (Hi-Rel) military/aerospace component, or a specific binning of a common device. a1458 optocoupler datasheet
Here is what you need to look for when reading the A1458 Optocoupler Datasheet. Based on recommendations in the A1458 optocoupler datasheet
CTR is defined as (IC / IF) * 100%. For the A1458, CTR varies by sub-grade: When a new optocoupler part number like A1458
| Rank | CTR (at IF=5mA, VCE=5V) | | :--- | :--- | | A1458-A | 50% - 150% | | A1458-B | 100% - 300% | | A1458-C | 200% - 600% |
Note for designers: The CTR degrades with temperature and age. A typical rule of thumb is to derate the CTR by 50% after 10 years of continuous operation at 50°C.