SN65HVD1781DR 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	R	output	Receiver data output. CMOS-level output presenting the demodulated state of the differential bus (A vs B). Drives up to ±8 mA (VOH ≥ 2.4 V, VOL ≤ 0.4 V).
2	RE	input	Receiver enable, active low. Drive low (or tie to GND) to enable the receiver output R; drive high (or tie to VCC) to place R in high-impedance. Combine with DE=low for standby/low-power mode.
3	DE	input	Driver enable, active high. Drive high to enable the differential driver (A/B); drive low to place the driver outputs in high-impedance. Combine with RE=high for standby/low-power mode (ICC ≤ 1 µA).
4	D	input	Driver data input. CMOS logic input whose state (with DE=high) sets the differential polarity between bus pins A and B. VIH ≥ 2 V, VIL ≤ 0.8 V.
5	GND	power_in	Ground reference for the device. Connect to the system ground plane.
6	A	bidirectional	Non-inverting RS-485 bus I/O. Driver output or receiver input, complementary to B. Fault-protected to ±70 V and ±16 kV HBM ESD; withstands -7 V to +12 V common-mode in normal operation.
7	B	bidirectional	Inverting RS-485 bus I/O. Driver output or receiver input, complementary to A. Fault-protected to ±70 V and ±16 kV HBM ESD; withstands -7 V to +12 V common-mode in normal operation.
8	VCC	power_in	Positive supply. 3.15 V to 5.5 V recommended operating range (4.5 V to 5.5 V per Pin Functions table for full RS-485 compliance). Bypass locally with a 0.1 µF ceramic capacitor to GND.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOIC-8
Category	Interface
Pins	8

Ordering variants

Same part, different packaging or reel option.

SN65HVD1781DR
SN65HVD1781DRD
SN65HVD1781DRP

CAD (KiCad official)

Symbol: SN65HVD1781DR
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
`sn65hvd1781dr.step`	122 KB	You want the bare part, or you mark your own boards.
`sn65hvd1781dr-etched.step`	2.4 MB	You want the part with `SN65HVD1781DR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 608 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 (34 pp, sha256 f8736dab94b48730, retrieved 2026-08-17, tier: manufacturer)
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