PS9821-1-A

Logic Output Optoisolators Overview

The CEL PS9821-1-A is a discontinued high-speed logic output optoisolator belonging to the NEPOC series. It features an active-low architecture with a GaAlAs LED input and open-collector output, providing 2500Vrms isolation voltage. The device supports data rates up to 15Mbps with a maximum propagation delay of 75ns and a common-mode transient immunity of 15kV/µs. Operating on a supply voltage of 2.7V to 3.6V, it handles a maximum DC forward current of 20mA and delivers 25mA output current. Packaged in an 8-SSOP surface-mount format, it functions within a temperature range of -40°C to 85°C.

Logic Output Optoisolators Feature Summary

• Active-low high-speed photocoupler utilizing a GaAlAs light-emitting diode for efficient optical transmission.
• Integrated signal processing circuitry combined with a photodiode to ensure stable logic-level output switching.
• High common-mode transient immunity capability designed to maintain signal integrity in electrically noisy environments.

Logic Output Optoisolators Applications

• High-speed digital communication interfaces requiring galvanic isolation
• Microcontroller-based systems needing noise-immune signal transmission
• Industrial control circuits operating within specified voltage and temperature limits

Logic Output Optoisolators Procurement Notes

Verify component authenticity carefully as this part is officially obsolete and no longer manufactured by CEL. Confirm that any available units are genuine original equipment manufacturer products rather than refurbished or counterfeit items. Check datasheet revisions to ensure compatibility with current design requirements before procurement.

Logic Output Optoisolators Selection Notes

Select this component only if legacy compatibility with the NEPOC series is required. Evaluate alternative high-speed optocouplers from current manufacturers if new designs allow. Ensure the active-low logic polarity matches the receiving circuit's input expectations. Verify that the 8-SSOP package dimensions fit the existing PCB footprint constraints.

Logic Output Optoisolators Part Context

This device is part of the NEC/Renesas CEL PS9821 family of high-speed optocouplers. It shares architectural similarities with the PS9821-2 variant but differs in logical output state. The series was designed to provide robust isolation for digital signals in compact surface-mount packages, serving as a bridge between low-voltage logic and isolated domains.

Logic Output Optoisolators Replacement Considerations

Public confirmed substitutes include PS9821-1-F3-AX from Renesas Electronics Corporation and HCPL-060L from Broadcom Limited. These alternatives offer direct functional replacements for the discontinued CEL part.

Logic Output Optoisolators FAQ

What is the typical forward voltage drop of the input LED?

The typical forward voltage (Vf) of the input side is 1.65V.

Does the device support single-channel operation?

Yes, the PS9821-1-A contains one isolated channel with a 1/0 input-to-output configuration.