| Pin Number | Name | Description | |------------|-------------|------------------------------------| | 1 | Anode (A) | Positive terminal of the IR LED | | 2 | Cathode (C) | Negative terminal of the IR LED | | 3 | Emitter (E) | Output phototransistor emitter | | 4 | Collector (C)| Output phototransistor collector |
| Rank | CTR Min (%) | CTR Max (%) | Conditions | |------|-------------|-------------|-------------| | A | 50 | 150 | I_F = 5 mA, V_CE = 5V, Ta=25°C | | B | 80 | 240 | I_F = 5 mA, V_CE = 5V, Ta=25°C | | C | 130 | 400 | I_F = 5 mA, V_CE = 5V, Ta=25°C | | D | 200 | 600 | I_F = 5 mA, V_CE = 5V, Ta=25°C | a1458 optocoupler datasheet
For digital logic interfaces (e.g., 5V to 3.3V), ranks A or B are sufficient. For analog applications or low I_F drive (e.g., 1 mA from a battery-powered MCU), ranks C or D provide higher sensitivity. Part 5: Switching Characteristics (Speed) The A1458 is not an ultra-high-speed device (like a logic gate optocoupler, e.g., 6N137), but it is adequate for most power supply feedback and low-speed data isolation (< 50 kHz). | Pin Number | Name | Description |