ADM485ARZ‑REEL Complete Datasheet Summary

1. Basic Device Information

• Part Number: ADM485ARZ‑REEL
• Device Type: 5V Low‑Power EIA RS‑485 / RS‑422 Differential Transceiver
• Manufacturer: Analog Devices Inc.
• Document Revision: Rev. F
• Package: 8‑Lead Narrow SOIC (R‑8, SOIC_N)
• Packaging: Tape‑and‑Reel
• RoHS Status: Compliant (Z suffix)
• Temperature Range: Industrial −40°C to +85°C
• Key Features: Half‑duplex, 5 Mbps, thermal shutdown, short‑circuit protection, receiver fail‑safe
• Bus Loading: 1/8 unit load; up to 32 transceivers per bus

2. Key Features

• Fully compliant with EIA RS‑485 and RS‑422 standards
• 5 Mbps maximum data rate
• Single 5 V ±5% supply operation
• Wide bus common‑mode range: −7 V to +12 V
• Low‑power BiCMOS process
• Thermal shutdown and output short‑circuit protection
• Fast propagation delays:
• High‑impedance outputs when disabled or powered off
• Receiver open‑circuit fail‑safe (logic high when inputs float)
• ESD protection on all inputs and outputs
• Latch‑up immunity via epitaxial layer

3. Typical Applications

• Low‑power RS‑485 systems
• DTE/DCE interfaces
• Local area networks (LANs)
• Packet switching & data concentration
• Data multiplexers
• ISDN equipment
• Industrial multipoint data buses

4. Pin Configuration (8‑Lead SOIC, Top View)

5. Truth Tables

Driver Operation

Receiver Operation

6. Absolute Maximum Ratings

• Supply voltage (VCC): −0.3 V to +7 V
• Receiver inputs (A, B): −9 V to +14 V
• Driver outputs (A, B): −9 V to +14 V
• Continuous output current: ±35 mA
• Operating temperature: −40°C to +85°C
• Storage temperature: −65°C to +150°C
• Power dissipation (SOIC): 450 mW

7. Recommended Operating Conditions

• Supply voltage (VCC): 4.75 V to 5.25 V
• Bus common‑mode voltage: −7 V to +12 V
• Temperature: −40°C to +85°C
• Data rate: Up to 5 Mbps

8. Key Electrical Specifications

• Driver
• Receiver
• Power
• Protection

9. Functional Description

• Half‑duplex differential transceiver with independent driver/receiver enables
• Driver: converts logic input to differential RS‑485 output
• Receiver: converts differential bus signal to logic output
• Thermal shutdown protects against overheating from bus contention or shorts
• High‑Z off‑state minimizes bus loading when not in use
• Fail‑safe receiver eliminates false outputs from floating inputs

10. Package & Ordering

• Part: ADM485ARZ‑REEL
• Package: 8‑Lead Narrow SOIC (R‑8)
• Industrial temp: −40°C to +85°C
• RoHS compliant
• Tape‑and‑reel packaging

11. Thermal Information (SOIC)

• Thermal resistance (θJA): 170°C/W
• Power dissipation: 450 mW