A1458 Optocoupler Datasheet !!top!!
Parameter | Symbol | Min / Typ / Max | Unit | Details :--- | :--- | :---: | :--- | :--- | VCC | 4.5 to 5.5 | V | Main power supply for output side. Input Voltage Range | VIN | 0 to VCC | V | Logic input voltage for the LED side. Forward Current (IF) | IF | 13 / 20 | mA | Typical 13mA, max 20mA. Forward Voltage (VF) | VF | 1.3 / 1.7 | V | Typical 1.3V, max 1.7V. Output Current (IO) | IO | 8 | mA | Max output current. Isolation Voltage | VISO | 3750 / 5300 | Vrms | Minimum 3750Vrms, up to 5300Vrms depending on variant. Current Transfer Ratio (CTR) | CTR | 15% to 30% | % | Ratio of output collector current to input forward current. The HCPL-1458 series is noted for higher CTR than the base "A1458". Data Rate / Speed | - | 15 | Mbps | Maximum data rate. Propagation Delay | tPHL / tPLH | 45 / 20 | ns | Delay from input to output (45ns typical for HCPL-A1458, 20ns typical for HCPL-1458). Common Mode Transient Immunity (CMTI) | CMTI | 15,000 | V/μs | Minimum value, excellent noise rejection. Operating Temperature | TOPR | -40 to +100 | °C | Wide industrial temperature range.
Based on field application notes from the datasheet, here are common issues:
VCE(sat)cap V sub cap C cap E open paren s a t close paren end-sub ): 0.1V to 0.4V, ensuring efficient switching. 3. Isolation Characteristics Isolation Voltage ( VISOcap V sub cap I cap S cap O end-sub a1458 optocoupler datasheet
) of 1.2 mA, it is highly efficient, making it ideal for low-power, high-density circuits.
| Parameter | Typical Expected Value | Why It Matters | | :--- | :--- | :--- | | | 3,750 Vrms – 5,000 Vrms | Safety compliance (UL, VDE). For A1458, check if it meets reinforced insulation. | | Current Transfer Ratio (CTR) | 50% – 600% (depending on bin) | The gain of the coupler. Low CTR (<50%) indicates an old or slow device. | | Rise/Fall Time (tr/tf) | 2 – 18 µs | Determines max switching speed (typically < 100 kHz for standard types). | | Input Forward Current (IF) | 50 mA (max) / 10 mA (typical) | Prevents burning out the internal LED. | Parameter | Symbol | Min / Typ /
The A1458 bridges the gap between low-power logic controllers (such as MCUs and FPGAs) and high-power electrical subsystems. According to the engineering data on UTSOURCE.net , the module features specific electrical and isolation performance profiles:
: The primary purpose of the A1458 is to provide a barrier between two circuits. On your PCB, ensure there is a clear physical gap (a slot or a "no-copper" area) under the optocoupler to maintain the high isolation voltage rating. This is often called a "moat." Forward Voltage (VF) | VF | 1
As environment temperatures rise, the maximum allowable collector power dissipation falls, meaning maximum system current must be derated. 6. Applications of the A1458 Optocoupler
Use a series resistor at the input (Anode, Pin 1) to limit the LED current to within the recommended operating range (typically
The CTR is not linear. It peaks at a certain forward current range (usually between 5mA and 15mA). Designing circuits with too little or too much input current can cause a dramatic drop in performance.
Its primary function is to transmit electrical signals between two isolated circuits using light as the transmission medium. This creates , meaning there is no direct electrical connection between the input and output. This is crucial for protecting sensitive low-voltage control circuits from high-voltage spikes, noise, or ground loops present in high-power sections of a system, such as motor drives, power supplies, or industrial machinery.