UM3085EESA from Union Semiconductor, in a SOP-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	RO	output	Receiver Output. If A-B > -50 mV, RO is high; if A-B < -200 mV, RO is low. High-Z in shutdown mode.
2	~{RE}	input	Receiver Output Enable (active low). Drive RE low to enable the receiver (RO active); RO is high impedance when RE is high. Drive RE high and DE low to enter low-power shutdown mode.
3	DE	input	Driver Enable (active high). Drive DE high to enable the driver outputs (A, B); outputs are high impedance when DE is low. Drive RE high and DE low to enter low-power shutdown mode.
4	DI	input	Driver Input. A low on DI forces output A low and output B high; a high on DI forces output A high and output B low. Has 100 mV input hysteresis on UM3085E.
5	GND	power_in	Ground reference (0 V).
6	A	bidirectional	Non-inverting Receiver Input and Non-inverting Driver Output (RS-485 differential line A). Input range -7 V to +12 V common-mode; ±15 kV HBM / IEC61000-4-2 air-gap ESD protected.
7	B	bidirectional	Inverting Receiver Input and Inverting Driver Output (RS-485 differential line B). Input range -7 V to +12 V common-mode; ±15 kV HBM / IEC61000-4-2 air-gap ESD protected.
8	VCC	power_in	Power Supply for RS-485 transceiver. Nominal +5 V ±5% (absolute max +7 V). Typical supply current 300 µA unloaded, 2 nA in shutdown.

Key specifications

Parameter	Value
Manufacturer	Union Semiconductor
Package	SOP-8
Category	Interface
Pins	8

Ordering variants

Same part, different packaging or reel option.

UM3085EESA
UM3088EESA
UM3085EEPA
UM3088EEPA

CAD (KiCad official)

Symbol: UM3085EESA
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`um3085eesa.step`	122 KB	You want the bare part, or you mark your own boards.
`um3085eesa-etched.step`	2.4 MB	You want the part with `UM3085EESA` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 578 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: Union Semiconductor datasheet (14 pp, sha256 5d1b6bed27594621, retrieved 2026-08-17, tier: lcsc)
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