Half-duplex RS-485/RS-422 transceiver running from a single 3.3 V supply. A driver and receiver share the A/B bus pair, with DE enabling the driver and RE the receiver, so one chip both sends and listens on a two-wire multidrop line up to 12 Mbps. It supports up to 32 nodes on a bus and holds valid receiver output for open, short, and idle lines. A standard 3.3 V RS-485 interface for industrial serial links.

Pinout

Pin	Name	Type	Function
1	RO	output	Receiver Output. When the receiver is enabled (RE low), if A − B > 200 mV then RO = high; if A − B < −200 mV then RO = low. Drives CMOS logic levels referenced to VCC (3.3 V).
2	RE	input	Receiver Output Enable (active low). A low level enables the receiver output RO; a high level places it in high impedance. If RE is high and DE is low, the device enters low power shutdown mode.
3	DE	input	Driver Output Enable (active high). A high level enables the differential driver outputs A and B; a low level places them in high impedance. If RE is high and DE is low, the device enters low power shutdown mode.
4	DI	input	Driver Input. With the driver enabled (half-duplex), a logic low on DI forces A low and B high; a logic high on DI forces A high and B low. CMOS input, VIH ≥ 2.0 V, VIL ≤ 0.8 V.
5	GND	power_in	Ground reference (0 V) for the transceiver.
6	A	bidirectional	Noninverting Receiver Input A and Noninverting Driver Output A (shared bus pin in half-duplex operation). Bus common-mode range −7 V to +12 V; receiver input impedance 12 kΩ minimum.
7	B	bidirectional	Inverting Receiver Input B and Inverted Driver Output B (shared bus pin in half-duplex operation). Bus common-mode range −7 V to +12 V; receiver input impedance 12 kΩ minimum.
8	VCC	power_in	Power Supply, 3.3 V ± 0.3 V. Absolute maximum 7 V to GND. Typical ICC = 1.1 mA.

Key specifications

Parameter	Value
Type	RS-485 / RS-422 transceiver (half-duplex)
Supply	3.3 V
Data rate	Up to 12 Mbps
Bus loading	Up to 32 nodes
Enables	DE (driver), RE (receiver)
Fail-safe	Receiver defined for open/short/idle
Package	SOIC-8

Ordering variants

ADM3485ARZ (SOIC-8)
ADM3485EARZ (SOIC-8, +/-15 kV ESD)
ADM3485ARMZ (MSOP-8)

CAD (KiCad official)

Symbol: Interface_UART:ADM3485xR (KiCad official)
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Analog Devices datasheet (20 pp, sha256 e7fcba7f9a3919f7, 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