The HCPL-1458 (also known as the A1458) is a high-speed, hermetically sealed logic gate optocoupler originally manufactured by Avago Technologies (now Broadcom). It is primarily used for electrical isolation in high-reliability and industrial applications. Key Features
High-Speed Performance: Supports data rates with a maximum propagation delay ( ) of 8 ns. Wide Power Supply Range: Operates on a VCCcap V sub cap C cap C end-sub
range of 3.0V to 5.5V, allowing flexibility for different logic levels.
High Noise Immunity: Provides high common-mode transient immunity (CMR) of at least 50 kV/µs.
Superior Isolation: Rated for an isolation voltage of 5300 Vrms. Low Power Consumption: Maximum supply current ( ICCcap I sub cap C cap C end-sub
) is approximately 1.2 mA, making it suitable for power-sensitive designs.
Hermetic Packaging: Available in an 8-pin hermetically sealed package (SOP-8 or similar), protecting internal components from environmental factors. Electrical Specifications Typical/Max Value Forward Current ( IFcap I sub cap F ) 20 mA (Max) Output Current ( ICcap I sub cap C ) Operating Temperature -55°C to +100°C Propagation Delay 35 ns at 10 kHz Common Applications
Industrial Control Systems: Protecting microcontrollers from high-voltage spikes and ground loops. 1458 optocoupler datasheet
Telecommunications: High-speed digital signal switching and line receivers.
Medical Equipment: Ensuring electrical isolation for patient safety in diagnostic devices.
Power Supplies: Used as a feedback element in switched-mode power supplies (SMPS). Comparison Note
Be careful not to confuse the HCPL-1458 with the LM1458 or MC1458. While they share the "1458" number, the LM1458 is a Dual Operational Amplifier and does not provide optical isolation.
If you are looking for specific pinout diagrams or price availability from distributors like Broadcom or Utsource, let me know. LM1458/LM1558 Dual Operational Amplifier datasheet (Rev. D)
The HCPL-1458 is an integrated opto-isolator that utilizes a short optical transmission path to transfer signals between two electrically isolated circuits. This isolation is critical for protecting sensitive low-voltage components, such as microcontrollers, from high-voltage spikes and reducing ground loop interference. Key Technical Specifications
Datasheets for the HCPL-1458 typically highlight its ability to operate at high speeds with minimal power requirements. The HCPL-1458 (also known as the A1458 )
Isolation Voltage: Provides high galvanic isolation, often rated at 3,750 to 5,000 VRMScap V sub cap R cap M cap S end-sub for one minute.
Speed and Timing: Designed for high-speed operation with typical propagation delays as low as 8 ns to 35 ns. Voltage Range: Operates within a flexible VCCcap V sub cap C cap C end-sub
range of 3.0 V to 5.5 V, making it compatible with both 3.3V and 5V logic systems. Current Consumption: Features low input forward current ( IFcap I sub cap F
) requirements, which reduces the load on driving circuits like microcontrollers.
Packaging: Commonly found in a hermetically sealed 8-pin DIP or SOP-8 package, which offers superior protection against moisture and environmental contaminants compared to standard plastic packages. Comparison: Optocoupler vs. Operational Amplifier
It is important to distinguish this component from the MC1458, which is a widely used dual general-purpose operational amplifier. HCPL-1458 (Optocoupler) MC1458 (Op-Amp) Primary Function Electrical Isolation & Signal Coupling Signal Amplification & Conditioning Internal Mechanism LED and Photodetector Dual Monolithic Silicon Op-Amp Typical Use Protecting MCUs from high voltage Summing, Integrating, Feedback loops Input/Output Optically coupled Directly coupled Applications
The unique hermetic sealing and high-gain characteristics of the HCPL-1458 make it suitable for specialized environments: Forward Voltage ($V_F$): Typically around 1
Industrial Automation: Isolating power supplies and driving power MOSFETs or IGBTs in motor control feedback loops.
Medical Equipment: Ensuring patient safety by isolating high-voltage power stages from sensitive diagnostic circuitry.
Communication Systems: Acting as an isolated line receiver for high-speed digital data transmission systems where noise immunity is critical. MC1458 data sheet, product information and support | TI.com
Note: There is no industry-standard optocoupler with the primary designation "1458." The "1458" is famously a dual operational amplifier (e.g., LM1458, UA1458). This paper addresses that ambiguity, clarifies the likely confusion, and provides a rigorous methodological framework for analyzing an optocoupler datasheet, using a real, similar device (e.g., 4N35) as a practical example.
The input side of an optocoupler is essentially an Infrared (IR) LED.
Author: Technical Analysis Division Date: October 2023
CTR is calculated as: CTR = (IC / IF) * 100%
A datasheet will show CTR graphs. For a generic optocoupler, CTR decreases as temperature rises and as the optocoupler ages (over years). For reliable digital communication, ensure your IC is at least 2x the required input current of your receiving chip.
The following specifications represent the typical characteristics of the PC1458 (and similar 4-pin DIP optocouplers like the PC817, which shares a nearly identical footprint and application).