ISO7721DWVR from Texas Instruments, in a SOIC-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	VCC1	power_in	Power supply for side 1 (input for channel B, output for channel A). Operating range 2.25 V to 5.5 V referenced to GND1. Decouple with a low-ESR ceramic capacitor (e.g. 0.1 µF) close to the pin.
2	OUTA	output	Digital output of channel A on side 1. Channel A is the reverse channel; this pin mirrors the logic level applied to INA on side 2. Drives push-pull CMOS levels referenced to VCC1/GND1 with IOH up to −4 mA at VCC = 5 V.
3	INB	input	Digital input of channel B on side 1. Channel B is the forward channel; the logic level driven here appears at OUTB on side 2. LVCMOS input thresholds referenced to VCC1 (VIH ≥ 0.7·VCC1, VIL ≤ 0.3·VCC1). Default output state (no F suffix) is high when input is lost.
4	GND1	power_in	Ground reference for side 1 (VCC1 return). Isolated from GND2 across the SiO2 isolation barrier.
5	GND2	power_in	Ground reference for side 2 (VCC2 return). Isolated from GND1 across the SiO2 isolation barrier.
6	OUTB	output	Digital output of channel B on side 2. Mirrors the logic level driven at INB on side 1. Push-pull CMOS output referenced to VCC2/GND2 with IOH up to −4 mA at VCC = 5 V.
7	INA	input	Digital input of channel A on side 2 (reverse channel). Logic level driven here appears at OUTA on side 1. LVCMOS thresholds referenced to VCC2 (VIH ≥ 0.7·VCC2, VIL ≤ 0.3·VCC2).
8	VCC2	power_in	Power supply for side 2 (input for channel A, output for channel B). Operating range 2.25 V to 5.5 V referenced to GND2. Decouple with a low-ESR ceramic capacitor (e.g. 0.1 µF) close to the pin.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOIC-8
Category	Comm/UART
Pins	8

Ordering variants

Same part, different packaging or reel option.

ISO7721DWVR
ISO7721DWVRDR
ISO7721DWVRD
ISO7721DWVRDWR

CAD (KiCad official)

Symbol: ISO7721DWVR
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`iso7721dwvr.step`	122 KB	You want the bare part, or you mark your own boards.
`iso7721dwvr-etched.step`	1.9 MB	You want the part with `ISO7721DWVR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 485 faces against 147 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Texas Instruments datasheet (38 pp, sha256 6cd4876010fb4841, retrieved 2026-08-17, tier: lcsc)
Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF