ADM3072EARZ - 3.3V Half-Duplex RS-485/RS-422 Transceiver, 15kV ESD | Analog Devices
MPN: ADM3072EARZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.51 | $3.51 |
| 10 | $3.16 | $31.60 |
| 100 | $2.86 | $286.00 |
| 500 | $2.68 | $1,340.00 |
| 1,000 | $2.55 | $2,550.00 |
ADM3072EARZ Overview
A RS-485/RS-422 transceiver is a differential line interface IC that converts between a single-ended UART/logic signal on the controller side and a robust differential signal on the cable side. RS-485 belongs to the TIA/EIA-485 family of standards, supporting multipoint, half-duplex or full-duplex links over twisted pair at distances up to 1200 m. Transceivers in this category are essential building blocks of industrial fieldbus, motor control, building automation, and process-control networks, sitting in the hierarchy: transceiver -> line driver/receiver -> interface IC -> signal conditioning -> wired connectivity.
Key features of the ADM3072E family include ±15 kV HBM ESD protection on the bus pins, true fail-safe receiver inputs that guarantee a logic-high output when the bus is open or shorted, hot-swap input structure on DE and RE for glitch-free board insertion, low power consumption, and 1/8 unit-load support that allows up to 256 nodes on the bus. The half-duplex pinout shares a single differential pair between driver and receiver.
The device operates from a single 3.0 V to 3.6 V supply and includes thermal shutdown and current-limit protection on the driver outputs. Internal slew-rate limiting reduces EMI and reflections on unterminated or short backplanes. The combination of fail-safe, hot-swap, and 256-node fan-out makes the part well suited to long-cable, multi-drop industrial networks.
Typical applications include industrial multipoint RS-485 networks, building automation and HVAC controllers, utility metering, motor control encoder/driver links, point-of-sale and access control panels, and any 3.3 V MCU/UART-to-RS-485 bridge. Pairing with a 3.3 V Cortex-M MCU (e.g., STM32, MAX32650, PIC32) provides a complete serial-port-to-fieldbus bridge.
When designing with this transceiver, ensure the bus is terminated with a 120 Ω resistor at each end of the cable, keep the DE/RE pull-up/pull-down network well-bounded for hot-swap behaviour, and add TVS diodes (such as SMAJ6.8CA) for surge protection beyond the built-in ±15 kV HBM ESD rating.
This page synthesizes distributor pricing, same-package drop-in alternatives (including ADM3070E, ADM3071E, ADM3073E, ADM3075E, ADM3076E and the MAX3072E cross-reference), and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ADM3072EARZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADM3070EARZ
✅ Drop-In📋 Reference alternative (not in catalog)
ADM3071EARZ
✅ Drop-In📋 Reference alternative (not in catalog)
ADM3073EYRZ
✅ Drop-In📋 Reference alternative (not in catalog)
ADM3076EYRZ
✅ Drop-In📋 Reference alternative (not in catalog)
MAX3072EASA+
✅ Drop-In📋 Reference alternative (not in catalog)
SP3072EEN-L/TR
✅ Drop-In📋 Reference alternative (not in catalog)
ADM3072EARZ Specifications
| Function | Transceiver |
| Protocol | RS-422, RS-485 |
| Number of Drivers/Receivers | 1/1 |
| Duplex | Half |
| Data Rate | 250 kbps |
| Supply Voltage | 3.0 V to 3.6 V |
| ESD Protection (HBM, bus pins) | ±15 kV |
| Receiver Input Sensitivity | ±200 mV (fail-safe threshold) |
| Bus Node Loading | 1/8 unit load (up to 256 nodes) |
| Operating Temperature | -40 °C to +85 °C |
| Package | SOIC-8 (R-8) narrow body |
| Mounting Type | Surface Mount |
| Hot-Swap Support | Yes (DE, RE pins) |
| True Fail-Safe Receivers | Yes |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| MSL Level | 1 (Unlimited) |
| 1ku List Price (starting) | $2.55 |
ADM3072EARZ Pin Configuration
| Pin 1 | RO — Receiver Output (logic-level, push-pull) |
| Pin 2 | RE — Receiver Enable (active-low); pulled low for normal operation, supports hot-swap |
| Pin 3 | DE — Driver Enable (active-high); pulled high to transmit, supports hot-swap |
| Pin 4 | DI — Driver Input (logic-level, TTL/CMOS) |
| Pin 5 | GND — Ground |
| Pin 6 | A/Y — Non-inverting differential bus pin (driver output / receiver input) |
| Pin 7 | B/Z — Inverting differential bus pin (driver output / receiver input) |
| Pin 8 | VCC — 3.0 V to 3.6 V supply |
Typical Applications
ADM3072EARZ is suitable for 6 applications: Industrial Multi-Drop RS-485 Networks, Building Automation and HVAC Controllers, Utility Metering and Smart Grid Links, Motor Drives and Encoder Interfaces, Point-of-Sale and Access Control Panels, Industrial Sensor and I/O Modules.
Industrial Multi-Drop RS-485 Networks
The ADM3072EARZ is purpose-built for half-duplex RS-485 fieldbus networks spanning up to 1200 m of twisted-pair cable. Its 1/8 unit-load receiver allows up to 256 nodes on a single bus, which is far beyond the 32-node limit of legacy 1 unit-load transceivers. The true fail-safe receiver guarantees a defined logic-high output when the bus is open, shorted, or idle, eliminating the need for external bias resistors at every drop. Compared with faster ADM3076E siblings, the ADM3072E's 250 kbps slew-rate-limited output reduces reflections and EMI on long unterminated backplanes. A typical node terminates the bus with a 120 Ω resistor at each end and pairs the transceiver with a 3.3 V Cortex-M MCU such as an STM32L4 or MAX32650.
Recommended
Building Automation and HVAC Controllers
BACnet MS-TP, Modbus RTU, and proprietary HVAC buses all run on 3.3 V RS-485 transceivers like the ADM3072EARZ. The ±15 kV HBM ESD rating protects the controller during cabinet installation, while hot-swap support on DE and RE allows live board insertion into a powered backplane without glitching the bus. The -40 °C to +85 °C industrial temperature range covers unconditioned rooftop and plant-room environments. The 256-node capacity easily accommodates large multi-tenant HVAC deployments, and the low quiescent current keeps standby power draw minimal for energy-star-rated controllers. A 3.3 V Cortex-M0+ host typically drives the UART side while the ADM3072E handles the differential cable.
Recommended
Utility Metering and Smart Grid Links
Electricity, water, and gas meters use the ADM3072EARZ for their AMR/AMI concentrator-side links where hundreds of meters share a single RS-485 trunk. The 1/8 unit-load and 256-node support allow a single concentrator to poll an entire apartment block or industrial sub-station, while the ±15 kV ESD rating and -40 °C to +85 °C range handle outdoor cabinet mounting. Fail-safe receiver behaviour prevents false meter reads when the bus is faulted, and the low-power 3.3 V supply supports battery-assisted meter designs. Termination follows the standard 120 Ω at both ends with optional bias resistors for idle-bus biasing.
Recommended
Motor Drives and Encoder Interfaces
Variable-frequency drives, servo amplifiers, and stepper controllers use the ADM3072EARZ for half-duplex RS-485 links between the drive and the motion controller, carrying torque command, position feedback, and parameter frames. The 250 kbps rate is fast enough for sub-ms update loops while the slew-rate-limited driver keeps motor-generated EMI off the bus. Hot-swap support lets technicians swap encoder cards without rebooting the drive, and the ±15 kV ESD rating withstands the high dV/dt environment near power stages. A typical design pairs the transceiver with an isolated 3.3 V supply (such as an ADuM5000) and a Cortex-M4 motor controller.
Recommended
Point-of-Sale and Access Control Panels
POS terminals, RFID readers, and access-control panels use the ADM3072EARZ to network over 3.3 V RS-485, where its ±15 kV ESD protects against static discharge from users, cables, and cash-drawer connectors. The half-duplex pinout saves board area and cost vs full-duplex designs, and the 1/8 unit-load allows long daisy-chained reader strings without bus-loading issues. Hot-swap DE/RE behaviour enables live swap of door controllers while the rest of the system stays online. The device operates from a single 3.3 V rail, allowing direct pairing with mainstream Cortex-M and PIC32 POS hosts without level shifters.
Recommended
Industrial Sensor and I/O Modules
Distributed I/O blocks and analog/digital sensor concentrators use the ADM3072EARZ for their backplane RS-485 trunk. The 256-node fan-out lets a single controller poll hundreds of field I/O modules, while the fail-safe receiver eliminates false-alarm transitions during fault conditions. The -40 °C to +85 °C range handles cabinet-free mounting on the factory floor, and the 3.3 V supply eases integration with modern low-voltage FPGAs and Cortex-M hosts. Engineers often add a small external TVS (SMAJ6.8CA) for surge immunity beyond the on-chip ±15 kV HBM rating.
Recommended
Recommended Products Summary
Engineering reference data for ADM3072EARZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADM3070EARZ | ADM3073EYRZ | ADM3076EYRZ | MAX3072EASA+ | SP3072EEN-L/TR |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices (Maxim) | MaxLinear |
| Package | SOIC-8 (R-8) | SOIC-8 (R-8) | SOIC-8 (R-8) | SOIC-8 (R-8) | SOIC-8 (NSOIC-8) | SOIC-8 (NSOIC-8) |
| Supply Voltage | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V |
| Data Rate | 250 kbps | 250 kbps | 500 kbps | 16 Mbps | 250 kbps | 250 kbps |
| Duplex | Half | Full | Half | Half | Half | Half |
| ESD Protection (bus pins) | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM |
| Bus Node Loading | 1/8 unit load (256 nodes) | 1/8 unit load (256 nodes) | 1/8 unit load (256 nodes) | 1/8 unit load (256 nodes) | 1/8 unit load (256 nodes) | 1/8 unit load (256 nodes) |
| True Fail-Safe Receiver | Yes | Yes | Yes | Yes | Yes | Yes |
| Hot-Swap Support | Yes (DE, RE) | Yes (DE, RE) | Yes (DE, RE) | Yes (DE, RE) | Yes (DE, RE) | Yes (DE, RE) |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- Largest 256-node fan-out in a 3.3 V half-duplex SOIC-8 RS-485 transceiver (vs MAX3072EASA+)
- Same SOIC-8 footprint across the entire ADM307xE speed/feature ladder (vs ADM3076EYRZ (16 Mbps) and ADM3073EYRZ (500 kbps))
- True fail-safe receiver with hot-swap DE/RE structure (vs Legacy RS-485 transceivers without fail-safe (e.g., MAX485))
Design Notes
Place a 100 nF decoupling capacitor as close as possible to the ADM3072E VCC pin (pin 8), with a 10 µF bulk capacitor on the same supply rail within 25 mm. Keep the differential A/Y and B/Z traces as a 100 Ω differential pair with matched length, and route them away from switching nodes such as MOSFET gates and clock lines. Add a 1 MΩ pull-down on DE and a 1 MΩ pull-up on RE if these pins are not driven by the MCU, to define idle bus state during MCU reset.
Do not forget the 120 Ω termination resistor at each end of the bus. A common mistake is to populate only one terminator, which causes reflections that appear as intermittent CRC errors at higher data rates. For multi-drop, ensure that stub branches off the main trunk are kept under 1/10 of the driver rise time × propagation velocity (≈ 10 cm at 250 kbps) to avoid standing-wave artefacts.
If the bus leaves the board, add an SMBJ6.8CA or similar TVS diode between each bus pin and ground, plus a 100 Ω series resistor and a 10 nF ceramic to form a π-filter. This complements the ADM3072E's ±15 kV HBM ESD protection and is essential for surge immunity to IEC 61000-4-5 in industrial environments. Keep the TVS within 10 mm of the connector and use a solid ground pour under the bus-side circuitry.
Estimated: at 3.3 V VCC, maximum supply current of 1.5 mA into an 8-pin SOIC with θJA of 120 °C/W, the quiescent power dissipation is ≈ 5 mW and the junction temperature rise above ambient is ≈ 0.6 °C - thermal performance is not a design constraint for this part. The driver can source up to 60 mA into a 60 Ω bus load during signalling, dissipating ≈ 3.6 mW additional; still negligible thermals.
Compliance Information
RoHS3 compliant per Analog Devices product page. MSL 1 (Unlimited) per ADM3072E datasheet and PartGenie analysis. REACH status reported as 'unaffected' by PartGenie. Not AEC-Q100 qualified; for automotive RS-485 designs, choose ADM3065E (lower speed) or consult Analog Devices automotive-grade transceivers.
