Part A
ADM3491ARZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 2506 PCS
- Package
- SOIC-14
- Series
- Interfaces - pilotes, récepteurs, émetteurs - récepteurs
Replacement verdict
Compatible functional replacement candidate
The ADM3491ARZ and ADM3488ARZN are both 3.3 V RS-485/RS-422 transceivers in the same 8-lead SOIC package, sharing a common footprint and supply domain, but they differ in driver/receiver configuration and data rate. The ADM3491ARZ offers full-duplex operation at up to 10 Mbps, while the ADM3488ARZN is a half-duplex device rated at 250 kbps, so the ADM3488ARZN can serve as a functional substitute only where half-duplex, lower-speed operation is acceptable and the board layout supports the pin-function differences.
Duplex Configuration
Validation required
Data Rate
Validation required
Package Type
High match
Supply Voltage
High match
Parts at a glance
Part B
ADM3488ARZN
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4406 PCS
- Package
- SOIC-8
- Series
- Interfaces - pilotes, récepteurs, émetteurs - récepteurs
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADM3491ARZ | ADM3488ARZN | Why it matters |
|---|---|---|---|
| Data Rate | 12 Mbps | 250 kbps | Determines the maximum communication speed the transceiver can support; a 12 Mbps part cannot be substituted where 250 kbps is sufficient but the reverse may not hold for high-speed buses. |
| Duplex Mode | Full duplex | Full duplex | Full-duplex devices allow simultaneous transmit and receive, which is essential for point-to-point links requiring bidirectional data flow. |
| Number of Drivers/Receivers | 1 driver / 1 receiver | 1 driver / 1 receiver | Defines the channel count per package; matching counts ensures the same bus topology can be supported without adding external components. |
| Receiver Input Impedance (Unit Load) | 1/8 unit load (up to 256 nodes) | 1/8 unit load (up to 256 nodes) | Lower unit-load receivers allow more nodes on a single RS-485 bus; both parts support up to 256 nodes, enabling large multi-drop networks. |
| Supply Voltage | 3.0 V to 3.6 V | 3.0 V to 3.6 V | Both operate from a 3.3 V nominal rail; matching supply ranges ensures the same power supply design can be reused. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range ensures reliable operation in harsh environments; identical ranges mean no derating differences. |
| Package / Mounting | 8-SOIC (surface mount) | 8-SOIC (surface mount) | Same package footprint allows drop-in PCB replacement without layout changes. |
| Fail-Safe Receiver | Yes (open/short circuit) | Yes (open/short circuit) | Fail-safe receivers guarantee a defined logic output when the bus is idle, open, or shorted, preventing indeterminate states in the network. |
| ESD Protection (Bus Pins) | ±15 kV (HBM) | ±15 kV (HBM) | High ESD tolerance protects the transceiver from electrostatic discharge during handling and field use, reducing field failures. |
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 | ADM3491ARZ | ADM3488ARZN |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Type | Transceiver | Transceiver |
| Protocol | RS422, RS485 | RS422, RS485 |
| Number of Drivers/Receivers | 1/1 | 1/1 |
| Duplex | Full | 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 ADM3491ARZ and ADM3488ARZN?
The ADM3491ARZ is a 3.3 V, full-duplex RS-485/RS-422 transceiver with a maximum data rate of 10 Mbps, while the ADM3488ARZN is a 3.3 V, full-duplex RS-485/RS-422 transceiver with a maximum data rate of 250 kbps. Both are offered in 14-lead SOIC packages, but the ADM3491ARZ includes a driver enable (DE) and receiver enable (RE) pin configuration that differs from the ADM3488ARZN, which has DE and RE pins as well but is optimized for lower-speed, slew-rate-limited operation.
Are the ADM3491ARZ and ADM3488ARZN pin-compatible?
Both devices are packaged in a 14-lead SOIC (R-14) and share the same pinout for the RS-485/RS-422 transceiver functions, including A, B, Y, Z, DI, RO, DE, and RE pins. However, designers should verify the exact pin function assignments against the respective Analog Devices datasheets, as the ADM3491ARZ and ADM3488ARZN may differ in pin labeling or enable logic polarity.
Can the ADM3491ARZ be used as a drop-in replacement for the ADM3488ARZN?
Not necessarily. Although both are 3.3 V full-duplex RS-485/RS-422 transceivers in 14-lead SOIC packages, the ADM3491ARZ supports up to 10 Mbps while the ADM3488ARZN is limited to 250 kbps with slew-rate-limited outputs. The higher slew rate of the ADM3491ARZ may cause higher EMI and reflections in networks designed for the ADM3488ARZN, so replacement requires validation of data rate, cable length, termination, and EMI performance against the target design.
What data rates do the ADM3491ARZ and ADM3488ARZN support?
The ADM3491ARZ supports a maximum data rate of 10 Mbps. The ADM3488ARZN supports a maximum data rate of 250 kbps and features slew-rate-limited driver outputs to reduce EMI and reflections.
Do both devices operate from a single 3.3 V supply?
Yes. Both the ADM3491ARZ and ADM3488ARZN are specified for operation from a single 3.3 V supply (typically 3.0 V to 3.6 V), making them suitable for low-power, 3.3 V RS-485/RS-422 systems.
What are the common-mode voltage ranges of the ADM3491ARZ and ADM3488ARZN?
Both the ADM3491ARZ and ADM3488ARZN feature a wide common-mode input voltage range of -7 V to +12 V, which exceeds the RS-485 standard requirement and supports robust operation in electrically noisy environments.
Are the ADM3491ARZ and ADM3488ARZN available in the same package type?
Yes. Both devices are offered in a 14-lead SOIC package (R-14 suffix in the part number). The ADM3491ARZ and ADM3488ARZN share the same package outline, which simplifies PCB layout reuse when switching between the two parts, provided the electrical differences are validated.
Which device is better suited for low-EMI applications?
The ADM3488ARZN is better suited for low-EMI applications because its driver outputs are slew-rate limited, which reduces high-frequency emissions and signal reflections on long cables. The ADM3491ARZ, with its 10 Mbps capability, has faster output edges and may require more careful PCB layout and termination to control EMI.