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onsemi FOD814ASD — Optoisolators

FOD814ASD Optoisolator – 5000Vrms, AC/DC Input

MPNFOD814ASD
End of Life

onsemi FOD814ASD, 1-channel optoisolator, 5000Vrms isolation, AC/DC input, transistor output, 50-150% CTR at 1 mA, -55°C to 105°C, 4-SMD gull wing, Tape & Reel / Cut Tape.

$0.71Ref. price · indicative, final on quote
onsemi FOD814ASD datasheet (PDF)
Packaging4-SMD, Gull Wing
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

FOD814ASD specifications
ParameterValue
Input typeAC, DC
Output typeTransistor
MountingSurface Mount
Voltage - isolation5000Vrms
Voltage - output70V
Voltage - forward (Vf)1.2V
Current - output (Channel)50mA
Current transfer ratio150% @ 1mA
Current - DC forward (If)50 mA
Operating temperature-55°C ~ 105°C
PackageTape & Reel (TR); Cut Tape (CT)
Case4-SMD, Gull Wing
Channels1
Vce saturation200mV
Rise (Fall time)4µs, 3µs

Product details

5000Vrms isolation with AC/DC input flexibility

The FOD814ASD is an onsemi optoisolator rated for 5000Vrms isolation in a 4-SMD gull-wing package. Its input accepts both AC and DC, which means a single part can sense line-voltage zero-crossings or DC logic levels without a separate bridge rectifier — a practical advantage for motor-drive feedback and industrial PLC input modules.

CTR at low forward current drives the LED budget

Current transfer ratio is specified at 1 mA forward current: minimum 50%, maximum 150%. At 1 mA the LED draws well under the 50 mA absolute maximum, keeping the input-side power budget tight. The 70 V output rating and 50 mA output current cover most 24 V logic rails and relay-coil interfaces.

Industrial temperature range and switching speed

Frequently asked questions

Does FOD814ASD accept AC input, and how does that differ from DC-only optoisolators like the FOD817ASD?

Yes, the FOD814ASD accepts both AC and DC input. The FOD817ASD is DC-only. For AC line sensing — 50/60 Hz zero-cross detection or phase-angle measurement — the FOD814ASD eliminates the need for an external bridge rectifier, saving board space and BOM cost.

What is the current transfer ratio (CTR) range for FOD814ASD?

This relatively tight binning means less variation in output drive strength across temperature and production lots, simplifying worst-case margin analysis in the receiver circuit.

Is FOD814ASD a direct replacement for FOD814A3SD?

The FOD814A3SD shares the same AC/DC input, transistor output, 5000Vrms isolation, and 4-SMD gull-wing package. The key difference is the suffix — 'SD' indicates Tape & Reel packaging, while 'A3SD' may carry a different CTR bin or temperature range. Verify the CTR and temp specs against your design before substituting.