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onsemi HCPL0731 — Discrete Semiconductors

HCPL0731 onsemi Optoisolator – 2-Ch Darlington, 2500Vrms

MPNHCPL0731
Active

onsemi HCPL0731, dual Darlington optocoupler, 2-channel, 2500Vrms isolation, 8-SOIC surface-mount package, 400%–5000% CTR at 500µA forward current.

$3.4100Ref. price · indicative, final on quote
onsemi HCPL0731 datasheet (PDF)
Packaging8-SOIC (0.154", 3.90mm Width)
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

HCPL0731 specifications
ParameterValue
Input typeDC
Output typeDarlington
MountingSurface Mount
Voltage - isolation2500Vrms
Voltage - output18V
Voltage - forward (Vf)1.35V
Current - output (Channel)60mA
Current transfer ratio5000% @ 500µA
Current - DC forward (If)20 mA
Operating temperature-40°C~85°C
PackageTube
Case8-SOIC (0.154\", 3.90mm Width)
Channels2
Turn on (Turn off time)300ns, 1.6µs

Product details

What the high CTR range buys your isolated I/O design

The HCPL0731 is a dual-channel Darlington-output optocoupler from onsemi, in an 8-SOIC package. Its current transfer ratio spans 400% minimum to 5000% maximum at 500 µA forward current — that wide gain window means you can pull the LED side with a standard logic-level output and still get a clean logic-level signal on the output side, even over temperature.

Key parametrics for your BOM review

Isolation rating is 2500 Vrms, sufficient for basic functional isolation in industrial control and PLC digital input modules. Turn-on time is 300 ns typical, turn-off 1.6 µs typical; the asymmetry matters if you are counting edges at a few hundred kHz. Forward voltage is 1.35 V typical, with a maximum DC forward current of 20 mA — the input LED is well within the drive capability of a 3.3 V or 5 V microcontroller pin through a series resistor.

Lifecycle and compliance at a glance

The package is 8-SOIC, supplied in Tube.

Frequently asked questions

What is the difference between HCPL0731 and HCPL0730?

The HCPL0730 is a single-channel Darlington optocoupler in the same 8-SOIC package. The HCPL0731 is the dual-channel variant. All other key ratings — isolation voltage, CTR range, output voltage, temperature range — are identical between the two. If your BOM calls for two isolated channels, the HCPL0731 saves board space versus two HCPL0730s.