Part A
ADM3485EAR
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3150 PCS
- Package
- SOIC-8
- Series
- Interface - Condutores, Receptores, Transceivers
Replacement verdict
Compatible functional replacement candidate
The ADM3485EAR and ADM3488ARZN-RL7 are both half-duplex RS-485/RS-422 transceivers in 8-lead SOIC packages with matched supply voltage and data-rate classes, making them a viable functional replacement pairing. However, the ADM3485EAR includes enhanced ESD protection and a full fail-safe receiver, whereas the ADM3488ARZN-RL7 offers a higher receiver input impedance suitable for higher node counts. Designers should validate ESD robustness requirements, fail-safe behavior, and bus loading before substituting one for the other in a qualified design.
Interface Standard
High match
Supply Voltage
High match
ESD Protection Level
Validation required
Receiver Input Impedance
Validation required
Parts at a glance
Part B
ADM3488ARZN-RL7
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5256 PCS
- Package
- SOIC-8
- Series
- Interface - Condutores, Receptores, Transceivers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADM3485EAR | ADM3488ARZN-RL7 | Why it matters |
|---|---|---|---|
| Data Rate | 10 Mbps | 250 kbps | Maximum signaling speed; a faster part can replace a slower one in many designs, but not vice versa if high throughput is required. |
| Duplex Mode | Half-duplex | Full-duplex | Determines whether simultaneous transmit and receive is possible; full-duplex and half-duplex parts are not directly interchangeable on the same bus wiring. |
| Number of Drivers / Receivers | 1 / 1 | 1 / 1 | Defines the transceiver channel count; matching counts is essential for pin and functional compatibility. |
| Supply Voltage | 3.3 V | 5 V | The operating rail must match the system supply; a 3.3 V and 5 V part cannot be swapped without level and supply changes. |
| Receiver Input Impedance (Unit Loads) | 1/8 unit load (up to 256 nodes) | 1 unit load (up to 32 nodes) | Lower unit load allows more transceivers on a shared RS-485 bus; affects maximum node count and bus loading. |
| Fail-Safe Receiver | Yes (open-circuit fail-safe) | Yes (open-circuit fail-safe) | Guarantees a defined logic state when the bus is idle or open, preventing spurious data; both provide this, aiding substitutability. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Defines the environmental envelope; matching ranges ensures the replacement meets the same thermal requirements. |
| Package / Mounting | 8-lead SOIC (surface mount) | 8-lead SOIC (surface mount) | Footprint and assembly compatibility; identical package and pinout allow drop-in board replacement. |
| ESD Protection (Bus Pins) | ±15 kV (HBM, bus pins) | ±15 kV (HBM, bus pins) | Robustness against electrostatic discharge on the bus; equal ratings mean comparable field reliability. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM3485EAR | ADM3488ARZN-RL7 |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Obsolete | Obsolete |
| Type | Transceiver | Transceiver |
| Protocol | RS422, RS485 | RS422, RS485 |
| Number of Drivers/Receivers | 1/1 | 1/1 |
| Duplex | Half | Full |
| Receiver Hysteresis | 50 mV | 50 mV |
| Data Rate | 10Mbps | 250kbps |
| Voltage - Supply | 3V ~ 3.6V | 3V ~ 3.6V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary differences between the ADM3485EAR and ADM3488ARZN-RL7?
The ADM3485EAR is a 3.3 V, half-duplex RS-485/RS-422 transceiver specified for data rates up to 12 Mbps, while the ADM3488ARZN-RL7 is a 3.3 V, full-duplex RS-485/RS-422 transceiver specified for data rates up to 12 Mbps. The key distinction is duplex configuration: the ADM3485EAR uses a single differential pair for half-duplex communication, whereas the ADM3488ARZN-RL7 uses separate driver and receiver pairs for full-duplex communication.
Are the ADM3485EAR and ADM3488ARZN-RL7 pin-compatible?
No. The ADM3485EAR is offered in an 8-lead SOIC package with a half-duplex pinout, while the ADM3488ARZN-RL7 is offered in a 14-lead SOIC package with a full-duplex pinout. The different package sizes and pin functions prevent direct PCB drop-in replacement without layout changes.
What supply voltage do both devices require?
Both the ADM3485EAR and ADM3488ARZN-RL7 operate from a single 3.3 V supply, with the datasheet specifying a supply voltage range of 3.0 V to 3.6 V.
What is the maximum specified data rate for each device?
Both the ADM3485EAR and ADM3488ARZN-RL7 are specified for data rates up to 12 Mbps per the Analog Devices datasheets.
How many nodes can each device support on an RS-485 bus?
Both the ADM3485EAR and ADM3488ARZN-RL7 are specified as supporting up to 32 nodes on a single RS-485 bus, consistent with a standard 1-unit-load receiver input impedance.
Do both parts include fail-safe receiver inputs?
Yes. Both the ADM3485EAR and ADM3488ARZN-RL7 datasheets specify fail-safe receiver inputs that guarantee a known logic-high receiver output when the bus inputs are open, shorted, or terminated but undriven.
What ESD protection is specified for the ADM3485EAR and ADM3488ARZN-RL7?
Both devices are specified by Analog Devices with ESD protection on the RS-485 bus pins. Designers should consult the respective datasheet for the exact ESD test standard and rating, as these details should be verified against the current manufacturer documentation for the specific grade ordered.
Which device should be selected for a full-duplex RS-485 link?
The ADM3488ARZN-RL7 should be selected for full-duplex links because it provides independent driver and receiver differential pairs. The ADM3485EAR is a half-duplex device and is not suitable for full-duplex operation without external configuration changes.