A1458 Optocoupler Datasheet May 2026

Dark current doubles approximately every 10°C. At high temperatures, it can become significant, so ensure your pull-up resistor and logic threshold account for this. Current Transfer Ratio (CTR) CTR is the gain of an optocoupler: (I_C / I_F) * 100%. The A1458 offers multiple rank options:

Many A1458 variants carry UL 1577, VDE 0884 (reinforced insulation), and CSA approvals. Always check the specific datasheet for regulatory marks if your design requires safety certification. Part 7: Typical Application Circuits (From Datasheet Examples) The A1458 optocoupler datasheet often includes reference circuits. Here are two common ones. Circuit 1: Digital Logic Isolation (High → Low) Scenario: Isolating a 24V PLC output to a 3.3V microcontroller input. a1458 optocoupler datasheet

| Model | CTR (%) | V_CEO (V) | t_on/t_off (μs) | Isolation (Vrms) | Best For | |-------|---------|-----------|-----------------|------------------|-----------| | | 50-600 | 80 | 5/4 | 5,000 | General purpose, wide CTR | | PC817 | 50-600 | 35 | 4/3 | 5,000 | SMPS feedback (lower V_CEO) | | 4N35 | 100 (min) | 30 | 10/10 | 5,000 | Hobbyist, older designs | | 6N137 | - (logic) | 7 | 0.075 | 5,000 | High-speed data (10 Mbps) | Dark current doubles approximately every 10°C

Switching speed is heavily dependent on the load resistor (R_L). A smaller R_L reduces the time constant (R_L * C_CE) but also reduces output voltage swing. For higher speeds (>100 kHz), consider a phototransistor optocoupler with a base access pin or a digital optocoupler. Part 6: Isolation Characteristics The isolation barrier is the primary reason to use the A1458. The datasheet provides the following isolation parameters: The A1458 offers multiple rank options: Many A1458