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Texas Instruments ISO7731FBDW — Digital Isolators

ISO7731FBDW Digital Isolator, 5000Vrms, 100Mbps, 16-SOIC

MPNISO7731FBDW
Active

Texas Instruments ISO7731FBDW, general-purpose digital isolator, capacitive coupling, 3 unidirectional channels, 100Mbps data rate, 5000Vrms isolation, 16-SOIC package, -55°C to 125°C operating temperature.

$3.2000Ref. price · indicative, final on quote
Texas Instruments ISO7731FBDW datasheet (PDF)
Packaging16-SOIC (0.295", 7.50mm Width)
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

ISO7731FBDW specifications
ParameterValue
TypeGeneral Purpose
Channel typeUnidirectional
MountingSurface Mount
Voltage2.25V ~ 5.5V
Voltage - isolation5000Vrms
Isolated powerNo
Operating temperature-55°C~125°C
Pulse width distortion4.9ns
PackageTube
Data rate100Mbps
TechnologyCapacitive Coupling
Case16-SOIC (0.295\", 7.50mm Width)
Channels3
Inputs - side 1/Side 22/1
Rise (Fall time)1.3ns, 1.4ns
Propagation delay tpLH (tpHL)16ns, 16ns
Common mode transient immunity85kV/µs

Product details

The Texas Instruments ISO7731FBDW is a three-channel, unidirectional digital isolator using capacitive coupling to pass signals across a reinforced 5000Vrms isolation barrier.

Key ratings and what they mean for your BOM

The 5000Vrms isolation voltage qualifies this part for reinforced insulation, so it can sit on the safety barrier between a motor-drive controller and the high-voltage power stage without needing a separate isolated DC-DC module.

That means you can qualify it into a new design without worrying about a forced respin inside the product lifecycle. The part is RoHS3 compliant and ships in a tube. For dual-sourcing resilience, the closest functional match in the same family is the ISO7830DWWR: same 100Mbps data rate, same 16ns propagation delay, but with all three channels on the same side (3/0 input count) and a higher 5700Vrms isolation rating. If your design needs the 2/1 channel split, the ISO7731FBDW is the one to hold; if you can rework the pin assignment, the ISO7830DWWR is a drop-in alternative on the same 16-SOIC footprint.

Frequently asked questions

Is ISO7731FBDW suitable for 100 Mbps data transmission?

Yes, the ISO7731FBDW is rated for a data rate of 100Mbps, with a maximum propagation delay of 16ns and pulse width distortion of 4.9ns, making it suitable for 100Mbps digital signals.

Is ISO7731FBDW suitable for SPI isolation?

Yes, the 100Mbps data rate and 16ns propagation delay provide enough margin for SPI clock rates up to 50MHz. The 2/1 channel count covers the typical SPI isolation need: MOSI, SCLK on one side, MISO returning. Note that chip-select (CS) would require an additional channel or external gating.

What is the difference between ISO7731FBDW and ISO7730?

The ISO7731FBDW has three unidirectional channels with a 2/1 input-to-output split. The ISO7730 (not in this evidence set) is a different variant in the same family — typically with a 3/0 or 1/2 channel configuration. Check the TI ISO773x datasheet for the exact channel arrangement of the ISO7730.

When sourcing ISO7731FBDW, what's the closest functional second-source?

The closest functional second-source in the same family is the ISO7830DWWR. It offers the same 100Mbps data rate, 16ns propagation delay, and 16-SOIC footprint, but with a 3/0 channel arrangement and a higher 5700Vrms isolation. If your design can accept the different channel mapping, it is a drop-in alternative.