The PS9821-1-F3 is a high-speed, high-CMR (Common Mode Rejection) photocoupler manufactured by California Eastern Labs (CEL), often using technology from NEC. It is designed to provide electrical isolation between circuits while transmitting digital signals. This makes it ideal for applications where safety isolation, noise immunity, or ground loop elimination is required.

Applications

• Industrial Automation: Programmable Logic Controllers (PLCs), motor drives, and other industrial control systems.
• Power Supplies: Switch-mode power supplies (SMPS) and inverters for feedback control and isolation.
• Communication Interfaces: Isolating RS-232, RS-485, and other communication lines.
• Medical Equipment: Patient monitoring systems and diagnostic equipment requiring safety isolation.
• Automotive Systems: Isolating control signals in automotive electronics.

Features

• High Speed: Offers fast switching speeds, enabling high data transfer rates.
• High Common Mode Rejection (CMR): Provides excellent noise immunity in harsh environments.
• High Isolation Voltage: Offers a high isolation voltage (typically several kilovolts) for safety.
• Low Input Current: Requires low input current for compatibility with various logic families.
• Open Collector Output: Features an open collector output, allowing for flexible voltage level translation.
• Compact Package: Available in a small surface-mount package, saving board space.
• Wide Operating Temperature Range: Operates over a wide temperature range, suitable for industrial applications.

Benefits

• Enhanced Safety: Provides electrical isolation to protect circuits and personnel from high voltages.
• Improved Noise Immunity: High CMR ensures reliable signal transmission in noisy environments.
• Faster Data Transfer: High speed enables high-speed communication between isolated circuits.
• Simplified System Design: Low input current simplifies interfacing with various logic circuits.
• Reliable Performance: Robust design ensures reliable operation in demanding applications.

Additional Details

The PS9821-1-F3 typically requires an external pull-up resistor on the output. The value of this resistor depends on the supply voltage and desired switching speed. The input LED typically requires a series resistor to limit the current. The datasheet provides detailed information on recommended operating conditions, electrical characteristics, and timing diagrams. It is commonly used in applications where signal integrity and safety isolation are critical.