Updated - A1458 Optocoupler Datasheet

CTR is defined as (IC / IF) * 100% . For the A1458, CTR varies by sub-grade:

): Typical 1.5 mA to 2.5 mA depending on the output logic state. Switching Performance (High-Speed Dynamics) Maximum 0.8 Propagation Delay to Logic High ( tPLHt sub cap P cap L cap H end-sub ): Maximum 0.8 Common Mode Transient Immunity (CMR): Typically

The device features rapid propagation delays ( 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) |

A look at the electrical parametric ratings from the HCPL-1458 / A1458 Datasheet reveals its optimization for low-power, high-speed digital applications: CTR is defined as (IC / IF) * 100%

A digital high signal (e.g., 5V from an Arduino or PLC) passes through a current-limiting resistor into Pin 1 (Anode).

Ensure the forward current ( IFcap I sub cap F Ensure the forward current ( IFcap I sub

: Provides isolation for power transistor gates (MOSFET/IGBT) to protect control circuitry from high-voltage spikes. Computing & Data