MAX3085 from Shanghai Siproin Microelectronics, 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. 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-impedance when RE is high.
2	RE	input	Receiver output enable (active-low). RO is enabled when RE is low; RO is high-impedance when RE is high.
3	DE	input	Driver output enable (active-high). Driver outputs A and B are enabled when DE is high, and are high-impedance when DE is low.
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 (when DE is high).
5	GND	power_in	Ground reference (0V).
6	A	bidirectional	Non-inverting RS-485/RS-422 bus line. Serves as receiver non-inverting input and driver non-inverting output. Handles -7V to +12V common-mode; 96k-ohm min input resistance (1/8 unit load); +/-15kV HBM ESD protected.
7	B	bidirectional	Inverting RS-485/RS-422 bus line. Serves as receiver inverting input and driver inverting output. Handles -7V to +12V common-mode; 96k-ohm min input resistance (1/8 unit load); +/-15kV HBM ESD protected.
8	VDD	power_in	Supply voltage input, +5V nominal (absolute max -0.5V to +6V). Decouple with 0.1uF ceramic to GND close to the pin.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

MAX3085

CAD (KiCad official)

Symbol: MAX3085
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Shanghai Siproin Microelectronics datasheet (11 pp, sha256 6179f730b209184a, 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