SSP3485U from Shanghai Siproin Microelectronics, in a MSOP-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. Drives high when A-B >= -0.05V, low when A-B <= -0.2V, and high (fail-safe) when A and B are open or shorted. High-Z when the receiver is disabled (RE = H).
2	RE	input	Receiver output enable (active low). Receiver output RO is enabled when RE is low, and forced to high impedance when RE is high. Bar over 'RE' indicates active-low signalling.
3	DE	input	Driver output enable (active high). Bus drivers A and B are enabled when DE is high and forced to high impedance when DE is low. Pulling DE low together with RE high places the device in shutdown (ISHDN max 10 uA).
4	DI	input	Driver (transmit) data input. When DE is high, a low on DI forces A low and B high; a high on DI forces A high and B low. TTL/CMOS compatible (VIH >= 2.0V, VIL <= 0.8V).
5	GND	power_in	Device ground reference (0 V). All signal voltages are referenced to this pin.
6	A	bidirectional	Non-inverting RS-485/RS-422 differential bus line. Serves as receiver input and driver output. Withstands ±15kV HBM ESD and -13V to +13V common-mode range; 1/8 unit-load input (RIN >= 96 kOhm) permits up to 256 nodes on the bus.
7	B	bidirectional	Inverting RS-485/RS-422 differential bus line. Serves as receiver input and driver output. Withstands ±15kV HBM ESD and -13V to +13V common-mode range; 1/8 unit-load input (RIN >= 96 kOhm) permits up to 256 nodes on the bus.
8	VDD	power_in	+5 V supply input (operating range 4.75-5.25 V; abs max -0.3 to +7 V). Bypass with a 0.1 uF ceramic capacitor to GND close to the pin. Typical ICC 450 uA (max 1.1 mA); shutdown current 10 uA max.

Key specifications

Parameter	Value
Manufacturer	Shanghai Siproin Microelectronics
Package	MSOP-8
Category	Comm/UART
Pins	8

Ordering variants

Same part, different packaging or reel option.

SSP3485UU
SSP3485U

CAD (KiCad official)

Symbol: SSP3485U
Footprint: Package_SO:MSOP-8_3x3mm_P0.65mm
3D model: MSOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ssp3485u.step`	123 KB	You want the bare part, or you mark your own boards.
`ssp3485u-etched.step`	2.3 MB	You want the part with `SSP3485U` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 541 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: Shanghai Siproin Microelectronics datasheet (11 pp, sha256 746800f4846f9992, 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