FODM121CR1

Overview

The FODM121CR1 is a single-channel transistor output optocoupler manufactured by onsemi. It features an NPN phototransistor output with a maximum collector-emitter voltage of 80 V and a continuous collector current of 80 mA. The device provides 3750 Vrms isolation voltage between input and output. Electrical characteristics include a forward voltage of 1.3 V (max) at 50 mA forward current, and a collector-emitter saturation voltage of 400 mV (max). The typical rise and fall times are 3 µs each. The component operates within a temperature range of -40°C to +110°C and is housed in a 4-SMD surface-mount package.

Feature Summary

• Provides galvanic isolation via optical transmission between input and output circuits
• Utilizes an NPN phototransistor for digital signal switching applications
• Designed for surface-mount assembly in compact electronic systems

Applications

• General-purpose digital signal isolation in industrial control systems
• Microcontroller interface circuits requiring electrical separation
• Power supply feedback loops for voltage regulation monitoring

Procurement Notes

Verify the specific suffix designation when ordering, as it determines the packaging format. Confirm availability status directly with authorized distributors or the manufacturer, as this part number may be subject to obsolescence or discontinuation notices. Ensure that the required insulation class and safety certifications align with the target application's regulatory standards before finalizing procurement.

Selection Notes

Select this component when a standard-speed transistor output isolator is required for cost-sensitive designs. Consider the 3 µs switching speed adequate for low-frequency digital communication. Evaluate the 3750 Vrms isolation rating against the system's working voltage requirements. Compare the CTR specifications if precise gain linearity is necessary for the application circuit design.

Part Context

This component belongs to the FODM121 family of transistor output optocouplers from onsemi. The family includes variants such as FODM121A and FODM121C, which differ primarily in Current Transfer Ratio (CTR) ranges. The CR1 suffix typically indicates a tape-and-reel packaging configuration, distinguishing it from tube-packaged versions like the FODM121A.

Replacement Considerations

Publicly documented substitutes include the FODM121R2. Verify pinout compatibility and electrical parameter equivalence before substitution.