FOD817ASD
onsemi
Needs validationlow risk
A strong match from the same manufacturer with identical key specs and a wider temperature range.
Best Alternatives to FOD817AS
Finding a substitute for the onsemi FOD817AS optocoupler involves matching its 4-SMD package, 5000Vrms isolation, and 70V VCEO. The most critical parameter to verify in any alternative is the Current Transfer Ratio (CTR) to ensure it fits within your circuit's design parameters.
AI replacement insight
Electrical riskmedium
CTR binning must be verified. Some alternatives have lower voltage ratings (VCEO).
Package risklow
Most candidates use a compatible 4-pin SMD package, but cross-vendor parts require footprint verification.
Sourcing risklow
The FOD817 and LTV-817 series are widely available from multiple manufacturers, reducing sourcing risk.
Can it be replaced directly?
Direct replacement for FOD817AS should use only Datasheet verified or Strong match candidates; many approved options still require engineering review.
Best replacement path
FOD817ASD is the strongest candidate, offering identical key parameters and a wider temperature range. However, all alternatives require verifying the Current Transfer Ratio (CTR) is compatible with the application.
Main risk
The primary risk when substituting FOD817AS is a mismatch in the Current Transfer Ratio (CTR). The target part has a broad 50-600% range, while many alternatives are binned into narrower ranges (e.g., 80-160%).
Recommended alternatives
4Alternative comparison matrix
| Feature / factor | FOD817AS | FOD817ASD | FOD817A3SD | LTV-816S-TA1-D | Compatibility / risk |
|---|---|---|---|---|---|
| Package | 4-SMD, Gull Wing | 4-SMD, Gull Wing | 4-SMD, Gull Wing | 4-pin SOP | 4-SMD, Gull Wing / 4-pin SOP — Package and pin count match.; FOD817A3SD: Package and pin count match.; LTV-816S-TA1-D: Package is likely compatible but requires footprint verification.; LTV-816S-TP-D-CU: Generic SMD package requires footprint verification. |
| Voltage | 70 V | 70 V | 70 V | 80 V | 70 V / 80 V — Collector-Emitter Voltage (VCEO) matches.; FOD817A3SD: Collector-Emitter Voltage (VCEO) matches.; LTV-816S-TA1-D: Higher VCEO is an upgrade.; LTV-816S-TP-D-CU: Higher VCEO is an upgrade. |
| Ctr | 50-600% | 50-600% | 80-160% | 300-600% | 50-600% / 80-160% / 300-600% — CTR range matches, but 'D' suffix may imply a specific bin. Verify if application is sensitive.; FOD817A3SD: CTR is restricted to a subset of the target's range.; LTV-816S-TA1-D: CTR is restricted to a subset of the target's range.; LTV-816S-TP-D-CU: CTR is restricted to a subset of the target's range. |
| Temperature | -30 to +100 °C | -55°C to +110°C | - | -50°C to +110°C | -55°C to +110°C / -50°C to +110°C — Wider operating temperature range is an upgrade.; LTV-816S-TA1-D: Wider operating temperature range. |
Application & sourcing insights
Questions & answers
Verified drop-in options for FOD817AS are limited in the current batch. Review candidates marked Strong match or Datasheet verified, and validate package, pinout, and electrical limits before committing a BOM change.