CTR is the gain of an optocoupler: (I_C / I_F) * 100%. The A1458 offers multiple rank options:
Example order code: A1458-B (CTR rank B)
: Protecting communication lines (RS-232, RS-485) and eliminating ground loops. Gate Driving : Specifically designed to drive power transistors like Power MOSFETs in high-power applications. Product Availability a1458 optocoupler datasheet
| Parameter | Symbol | Value | Unit | Condition/Note | | :--- | :--- | :--- | :--- | :--- | | | IF | 20 (Max) | mA | DC Input current | | Forward Voltage | VF | 1.3 (Typ) / 1.7 (Max) | V | IF = 10 mA | | Peak Transient Current | IF(trans) | 1 | A | Pulse width ≤ 1 µs | | Supply Voltage (Output) | VCC | 4.5 - 5.5 (Recommended) | V | -- | | Output Supply Voltage Range | VCC | 0 - 20 | V | Absolute Maximum rating | | Output Current | IO | 8 (Max) | mA | -- | | High Level Output Current | IOH | -0.4 to -8 | mA | -- | | Low Level Output Current | IOL | 8 | mA | -- | | Data Rate | -- | 50 (Max) | MBd | -- | | Propagation Delay (tPLH) | -- | 45 (Max) | ns | -- | | Propagation Delay (tPHL) | -- | 45 (Max) | ns | -- | | Current Transfer Ratio (CTR) | -- | 15% to 30% | % | -- | | Isolation Voltage (Withstand) | VISO | 5000 (Min) | Vrms | -- | | Common Mode Rejection (CMR) | | 15,000 (Min) | V/μs | For HCPL-1458 | | Operating Temperature | TA | -40 to +100 | °C | -- | | Storage Temperature | TSTG | -55 to +125 | °C | -- | | Lead Solder Temperature | -- | 260 | °C | For 10 sec (DIP package) |
In environments with heavy machinery, electromagnetic interference (EMI) can ruin data signals. The A1458 "cleans" the signal by transmitting it via light. CTR is the gain of an optocoupler: (I_C / I_F) * 100%
The HCPL-A1458 stands out as an active isolation component, which distinguishes it from typical signal-transfer isolators (like the common PC817). Instead of simply transferring a digital state or analog level, this optocoupler utilizes a specialized logic or gate-drive output stage to ensure clean, high-speed switching of power devices. This mitigates the classic performance bottleneck where low-gain phototransistors degrade switching speed. 📋 Technical Specifications Outline
Traditional optocouplers suffer from high base-collector capacitance in their phototransistors, slowing down switching. Devices like the HCPL-A1458 bypass this by utilizing a separate photodiode detector paired with integrated amplification, boosting speed up to 100 times. Product Availability | Parameter | Symbol | Value
The latency between the input trigger and output state switch, enabling high-frequency digital logic communication. 3.0 V to 5.5 V
Optocouplers have a "Rise Time" and "Fall Time." If you are sending high-speed PWM signals (above 10kHz), check the datasheet for the switching speed to ensure the signal doesn't become distorted.
$$CTR = \fracI_CI_F \times 100%$$