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onsemi FOD817 — Optoisolators

FOD817 onsemi Optoisolator 5 kV Transistor Output 4-DIP

MPNFOD817
Active

onsemi FOD817, single-channel DC-input transistor-output optoisolator, 5000Vrms isolation, 4-DIP through-hole package, 50%–600% CTR at 5 mA, -55°C to 110°C operating range.

$0.4800Ref. price · indicative, final on quote
onsemi FOD817 datasheet (PDF)
Packaging4-DIP (0.300", 7.62mm)
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

FOD817 specifications
ParameterValue
Input typeDC
Output typeTransistor
MountingThrough Hole
Voltage - isolation5000Vrms
Voltage - output70V
Voltage - forward (Vf)1.2V
Current - output (Channel)50mA
Current transfer ratio600% @ 5mA
Current - DC forward (If)50 mA
Operating temperature-55°C ~ 110°C
PackageTube
Case4-DIP (0.300\", 7.62mm)
Channels1
Vce saturation200mV
Rise (Fall time)4µs, 3µs

Product details

5 kV isolation in a 4-DIP through-hole package

The FOD817 is a single-channel optoisolator from onsemi delivering 5000Vrms galvanic isolation between a DC input LED and a phototransistor output, housed in a 4-DIP (0.300", 7.62mm) through-hole package. Its current transfer ratio spans 50% minimum to 600% maximum at If=5 mA, giving the designer a wide margin to set the LED forward current against the required output collector current without overdriving the input.

Switching speed and output drive capability

The output transistor can sink up to 50 mA continuous with a maximum Vce saturation of 200 mV, so it can drive a logic input or a small-signal relay directly without a buffer transistor. Maximum output voltage is 70 V, and the LED forward voltage is typically 1.2 V at If=20 mA; the forward current should not exceed 50 mA absolute maximum.

Frequently asked questions

What is the difference between FOD817 and PC817?

Both are single-channel 4-DIP transistor-output optoisolators with similar pinouts and isolation ratings. The FOD817 is an onsemi part; the PC817 is a Sharp (now part of Qorvo) part. The main parametric difference is the CTR range — the FOD817 specifies 50%–600% at 5 mA, while the PC817 typically offers narrower CTR bins (e.g., 80%–160%, 130%–260%). Check the CTR bin of your PC817 reference before substituting.